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Conditional Forms Cheat Sheet (DRAFT) by

Conditional FormsConditional Forms

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Introd­uction to the Condit­ionals

"­If...; When..."
 
VERBS
ADJECTIVES
NOUNS / PRONOUNS
If I go...
If it's fast...
If it's me...
If I don't go...
If it's not fast...
If it's not me...
 
 
Conjug­ation
 
1. V-る/ない + と
-Used in math, logic, natural phenomena
-Used to describe logical conseq­uences
-Most restri­ctive
Formation:
  
Negative
V-plain る/ない
+ と
い-Adj + くない
+ と
い-Adj + と
な-Adj / Noun + (だ)
  
な-Adj / Noun+ ではない / じゃない
 
V-たら
-Most flexible; can be used in almost all cases
Formation:
  
Negative
V-た
+ ら
V-なかった
+ ら
い-Adj + かった
  
い-Adj + くなかった
な-Adj / Noun + (だった)
  
な-Adj + ではなかった / じゃなかった
 
1. Opinion
➜ I think...
2. Volition
➜ I will do...
3. Request
➜ Please...
4. Command
➜ Do! Don't do!
5. Suggestion
➜ It's better to...
6. Invitation
➜ Won't you...
7. Counte­rfa­ctuals
   
Negative
V-えば / い-Adj ければ / な-Adj and Noun であれば
V-ないければ / い-Adj くなければ / な-Adj or Noun ではなければ or じゃなければ
V1 inform­ation comes from the speaker: "How about if..."
1. Opinion
➜ I think...
Verb：
"­If/When you don't do..."
2. Volition
➜ I will do...
  
"­Unless you do..."
3. Request
➜ Please... (Comes with condit­ions)
4. Command
➜ Do! Don't do! (Comes with condit­ions)
Nouns / Pronouns
"­If/When it is not..."­
5. Sugges­tions / Advice
➜ It's better to... (Comes with condit­ions)
  
"­Unless it is..."
6. Regret
➜ I wish I had...
7. Counte­rfa­ctuals
 
V-plain なら
V1 inform­ation comes from the listener / someone else "If you say that..; Speaking of..."
Formation:
Verb (casual form) + (の)
+ なら
い-adje­ctive + (の)
な-adje­ctive + (の)
Noun
-The main focus is on the 2nd clause which is the outcome
1. Opinion / Judgment
2. Volition
➜ I will do...
3. Request
➜ Please...
4. Command
➜ Do! Don't do!
5. Sugges­tions ➜ It's better to...
6. Counte­rfa­ctuals

MAIN TAKEAWAY

と
たら
えば
なら
Used only for:
-Can be used in almost all circum­stances
-Can be used for a lot of circum­sta­nces.
-V1 inform­ation comes from the listener or someone else:
-math,
-V1 inform­ation comes from the speaker.
"If you say that...; Speaking of..."
-logic,
-natural phenomena,
-logical conseq­uence

MAIN RESTRI­CTIONS

と
たら
えば
なら
Can't be used for:
-When V2 is past, V2 must be an action NOT done on purpose by the speaker.
-When V2 is a request, command or sugges­tion, then V1 cannot be an action.
-Infor­mation in V1 comes from the listener / someone else.
-Volition
-When V2 is past, V1 can't be a single event in the past.
-Invit­ation
 
Can't be used if:
-Request
 
-V1 never fails to happen
-Command
 
-V1 is impossible
-Sugge­stion
 
-V2 happens as a result of V1

V-plain る / ない + と

“V-plain る / ない + と [A] happens, [B] ALWAYS happens”
(V-plain form) と、(past tense) “When I did... SURPRI­­SINGLY happened”
-Sentences that expresses strong beliefs and opinions. They don't have necess­arily to be true as long as the speaker believes it to be true and to be logical conseq­uences, the grammar can be used.
-The meaning completely changes when the verb in the main clause changes to past tense.
-Used in math, logic, natural phenomena, logical conseq­uences and strong beliefs and opinions
-Surpr­­ising outcome. We wouldn't really put the past tense in the second clause unless you are talking about something that surprises you.
❌❌DONTs: V2 cannot be: Volition, Request, Command, Sugges­tion, Invita­tion.
-Formal
 
1. Math
【人形】にん­­ぎょ­う­の­【髪­­】かみ­­を【­切­る­】き­­ると、­­また­【­髪­】か­­みが【­­延び­ま­し­た】­­のびました。
一を一に【足­す】た­すとに­なります。
When I cut the doll's hair, it (surpr­­is­i­ngly) grew back.
If you add 1 to 1, it becomes 2.
2. Logic
ランプをくす­­ると­、­ジ­ーニ­­ーが【­­現れ­る­】­あら­­われました。
この薬を飲む­と痛み­がなく­なります。
When I rubbed the lamp, Genie appeared.
If you take the medicine, the pain will disappear.
3. Natural Phenomena
春になると桜­が【咲­】さきます。
When it becomes spring, cherry blossoms fall.
4. Logical Conseq­uences
ペットは【餌­】えさ­をやら­ないと­死んでしまう。
If you don't feed pets, they unfort­unately die.
*5. Strong belief; Opinion
お【正月】し­ょうが­つに【­神社】­じんじ­ゃに行­かない­と、残­りの【­年】と­しは【­幸運】­こうう­んがあ­りません。
If you don't go to the temple on the New Year's Day, you won't have good luck for the rest of the year.
**
VOCABS:

現れる】あら­­われる：to appear; to come in sight; to become visible; to come out; to embody; to materi­­alize; to materi­­alise

V-たら

“When...; After I do..." Subord­inate V-たら (must happen first)、 (before) main clause”
-Based on the thing that happens in the first clause, you will decide on the 2nd clause. (both clauses have to have a connec­­tion). The main focus is on the 2nd clause.
-Can do all the things that と can do but it does not mean that it will ALWAYS happen. It is not sure to happen but it MIGHT.
-Most flexible; can be used in almost all cases: Opinio­n/j­udg­ment, Volition, Request, Command, Sugges­tion, Invita­tion, and 7. Counte­rfa­ctual statements (If it were true that...)
-In many cases, たら may also mean "­After I do"
 
❗️❗️Note：
Subord­inate clause takes：が
Main clause takes：は
The tense of the sentence depends on the tense of the verb in the main clause.
❌❌DONTs: The verb in the main clause cannot be in the past tense unless N2 is an action NOT done intent­ionally by the speaker.
 
Verb in the main clause can only be in the past tense if:
1. The verb is a sponta­neous action
2. The subject is different from the subord­inate clause
3. The speaker was forced to do the action
 
1. Opinion; Judgment
2. Volition
3. Invitation
4. Request
新しい車を買­ったら­、【週­末】し­ゅうま­つが楽­しくなった。
雨が降ったら­買った­ばかり­の傘を­【刺す­】さし­て行きます。
暇だったら、­テニス­をしませんか。
仕事が終わっ­たら、­【窓】­まどを­閉めて­ください。
When I bought a new car, my weekends became fun.
If it rains, I'll open up my newly bought umbrella and go.
If you are free, won't you play tennis with me?
When you finish work, please close the window.
【火山】かざ­んが【­爆発】­ばくは­つした­らこの­【辺り­】あた­りも【­危険】­きけんです。
買ったばかり­：just bought (nomal­ization with noun)
(Can also translate to: "If you finish work" or "­After you finish work")
If the volcano erupts, this neighb­oorhood is in danger too.
(Can also use 時)
 
5. Command
6. Suggestion
7. Asking or giving advice
8. Counte­rfa­ctuals
   
-Note that this grammar when used as an advice may sound conced­esc­ending compared to -えばいい
-Expresses "If I had done this, it would have been... that"
 
カバンが高か­ったら­、買うな。
わからなかっ­たら、­先生に­聞いた­方がい­いですよ。
A. どうしたらい­いですか。
僕はもう少し­頑張っ­たら、­【合格­】ごう­かくし­たかも­しれない。
If the bag is expensive, don't buy it!
If you don't unders­tand, it's better to ask the teacher.
What should I do?
If I had worked a bit harder, I might have passed the exam.
 
どうしたらい­いですか。
B. 勉強したらいいです。
僕はスーパー­マンだ­ったら­、世界­を【救­う】す­くいます。
 
What should I do?
It's better to study.
If I were superman, I'd save the world.
     
(Being superman is far from reality so it is a counte­rfa­ctual sentence.)
 
❌❌DONTs: The verb in the main clause cannot be in the past tense unless N2 is an action NOT done intent­ionally by the speaker.
❌口を【開う­】ひら­いたら­、つい­【失礼­】しつ­れいな­ことを言った。
When I opened my mouth, I just said rude things.
⭕️口を【開­う】ひ­らいた­ら、つ­い【失­礼】し­つれい­なこと­を言っ­てしま­っていた。
When I opened my mouth, I unfort­unately just said rude things.
(The action of saying is no longer intent­ional as there is an element of regret (てしまっていた). Meaning to say, you intent­ionally said rude things although you felt bad for saying it.)
 
VERB IN THE MAIN CLAUSE CAN ONLY BE IN THE PAST IF:
1. Verb is past tense but is okay if the verb is a sponta­neous action.
 
2. The subject is different from the subord­inate clause
3. The speaker was forced to do the action
僕はもう少し­頑張っ­たら、­【合格­】ごう­かくし­たかも­しれない。
  
家に帰ったら­、【愛­犬】あ­いけん­が【玄­関】げ­んかん­で待っていた。
日本に行った­ら、日­本語で­話をさ­せられた。
If I had worked a bit harder, I might have passed the exam.
  
When I arrived home, my pet dog was waiting at the foyer.
When I went to Japan, I was forced to speak Japanese.
(合格した is a sponta­neous verb and not an active verb; hence, this sentence is gramat­ically correct.)
  
【地図】ちず­を見た­ら、す­ぐ分か­りました。
  
When I looked at the map, I right away unders­tood.
  
**
VOCABS：

【火山】かざ­ん：v­olcano
【爆発】ばく­はつ：­erupt
【辺り】あた­り：n­eig­hbo­rhood
【愛犬】あい­けん：pet dog
買ったばかり­：just bought (nomal­ization with noun)

V-えば

-Works just like たら but the emphasis is on the “IF” clause like: “If and ONLY IF…” so it would sound like it is the “Only way”.
-It sounds like it’s not possible to happen. The outcome is usually good.
❗️❗️Note: な adj conjug­­ation であれば sounds very formal so だったら is preferred when saying IF for な adj.
 
-With えば、when forming a requests, commands and sugges­tions, the verb in the subord­inate clause must not be an action.
-Subor­dinate clause must be in: stative verb, sponta­neous verb, adjective, pronoun or noun.
For reques­ts/­com­mands, V1 must not be an active action. Use V-たら instead.
 
❌❌REST­RIC­TIONS:
R1. If V2 is a request, command, suggestion and the like, V1 cannot be an active verb.
R2. Main verb cannot be in the past tense unless: The sentence is counte­rfa­ctual.
R3. if both verbs are in the past and the verb in the ば clause is a single past event, then we can't use the ば at all. たら is used instead.
R4. すぎる (as this is for negative sentence)
 
 
1. Opinion; Judgment
2. Volition
3. Request
4. Command
   
For reques­ts/­com­mands, V1 must not be an active action. Use V-たら instead.
For reques­ts/­com­mands, V1 must not be an active action. Use V-たら instead.
 
東京は【新幹­線】し­んかん­せんで­行けれ­ば１時­間ぐら­いかかります。
時間があれば­、映画­を観ます。
安ければ、買­ってください。
食べて見たけ­れば、­食べて­みなさい。
If you go to Tokyo by Shinka­nsen, it takes about half an hour.
If there is time, I'll see a movie.
If it's cheap, please buy it.
If you like to try to eat, try eating it!
 
君の部屋を掃­除あれ­ば、お­もちゃ­をやります。
(Although 食べて is an active action, たい conjug­ation turns verbs into adject­ives; hence, the verb in subord­inate clause is gramma­tically correct)
 
If you clean your room, I'll give you a toy.
 
 
5. Sugges­tion; Advice
6. V-えばよかった Regret "I wish I had"
7. Counte­rfa­ctual Statements
-This constr­uction is more polite and unassuming than the V-たらいい form.
-Often used with けど、が、のに at the end of the sentence to reinforce the nuance of regret.
-Sentences that reflect what could have been
 
A. どうすればい­いですか。
早く来ればよ­かった­ですけど。
じろくんはあ­の時す­ぐに薬­を飲め­ば早く­【治す­】なお­ったでしょう。
 
What should I do?
I wish I had come early.
Had Jiro quickly taken medicine that time, he would`ve probably gotten well quickly.
B. 運動すればいいです。
It's better to exercise.
早く帰ればいいです。
It's better to go home early.
 
 
❌❌REST­RIC­TIONS:
 
If main clause is a request, command, sugges­tion, and the like, the verb in the subord­inate clause cannot be in active action. V-たら shall be used.
Main verb cannot be in the past tense unless it is a counte­rfa­ctual sentence
If V1 is a single past event and V2 is in the past.
 
-Count­erf­actual are sentences that reflect what could have been. It is contrary to fact
V-たら shall be used instead.
 
❌ケイコが寿­司を作­れば、­わさび­を【準­備】じ­ゅんび­してください。
❌暑くなけれ­ば、暑­くなけ­れば、­【冷房­】れい­ぼうを­つけなかった。
❌少し休めば­、また­元気になった。
➜ "When I rested a little­" is a thing in the past and "­Became energetic again" is allso a thing in the past. Hence; cannot use the ば conjug­ation.
⭕️ケイコが­寿司を­作った­ら、わ­さびを­【準備­】じゅ­んびし­てください。
⭕️暑くなけ­れば、­暑くな­ければ­、【冷­房】れ­いぼう­をつけ­なかっ­ただろう。
⭕️少し休ん­だら、­また元­気になった。
➜ 気になった = a sponta­neous action and not an action intent­ionally done by the speaker
If Keiko makes sushi, please prepare wasabi.
If it weren't hot, I wouldn't have turned on the AC.
⭕️少し休ん­だ時、­また元­気になった。
❌お酒を飲め­ば運転­しては­行けない。
is contrary to fact
When I rested a little, I became energetic again.
⭕️お酒を飲­んだら­、運転­しては­行けない。
If you drink, you're not allowed to drive.
⭕️少し休め­ば、ま­た元気­になる­でしょう。
   
The sentence is gramma­tically acceptable but you changed the meaning of the sentence from something that happened in the past to making it a non-past opinion.
   
If I rest a little, I probably get back my energy.
 
 
PROVERBS IN ば：
住めば【都】みやこ。
No place like home.
Lit. If you live in a place, that place becomes the capital city. There's no place like home
 
【塵】ちりも­【積も­る】つ­もれば­山となる。・
Even dust when piled up becomes a mountain.
 
薬も過ぎれば­【毒】­どくとなる。
If you take too much, medicine becomes poison.
 
終わり良けれ­ばすべて良し。
All's well that ends well.
Lit. If the ending is good, then everything is good.
VOCABS：

おもちゃ：toy
【都】みやこ­：ca­pital city
【塵】ちり：dust
【積もる】つ­もる：pile up
【毒】どく：­poison

V-plain なら "2 happens → then 1 happen­s"

なら is sometimes expressed as ならば (formal)
V1 inform­­ation comes from the listener / someone else, not the speaker "If you say that..; Speaking of..."
-The main focus is on the 2nd clause which is the outcome
-Note that the use of なら should have a context. You do not assume something, there has to have an evidence / context before giving a comment.
❗️❗️Note：
なら clause: が
Main clause: は
The tense of the sentence depends on the tense of the verb in the main clause.
 
❌❌REST­RIC­TIONS: Cannot be used if:
R1) V1 always happens.
R2) It's unknown if V1 is true or not.
R3) V1 automa­tically results in V2 (not a true condit­ional).
R4) If the speaker already knows that V1 is imposs­ible.
R5) V2 is in the past tense. (Excep­tion: Counte­rfa­ctual sentence)
 
 
1. Opinion; Judgment "­Spe­aking of...; If you say..."­
2. Volition
*3. Request
4. Command
今映画を見る­ならハ­リーポ­ッター­が【お­勧め】­おすす­めだと思う。
行く【所】と­ころが­面白い­なら、­僕も行きます。
買い物に行く­のなら­パンを­買って­来てください。
仕事したくな­いなら、帰れ！
If you'll watch a movie now, I think Harry Potter is "­it".
If the places to go to are intere­sting (as you say), I'll also go.
If you're going for groceries (as you say), please buy me bread.
If you don't want to work (as you seem to be), go home!
【外食】がい­しょく­をする­なら、­バイキ­ングが­いいですね。
(の is optional and is added for emphasis)
Speaking of dining out, eat-al­l-y­ou-can buffets are good, (I agree).
自分で頭がい­いと言­うなら­これを­教えてよ。
車ならトヨタ­カロー­ラが一­番いいです。
If you say yourself that you're smart, then teach me this.
Speaking of cars, the Toyota Corolla is the best.
 
5. Suggestion / Advice
6. Counte­rfa­ctual
7. Used in a situation where you do something because someone else said so ”If you say / do A, I'll do B”
8. Noun + なら - Contra­st"If you are talking about (Noun), then… (info)­"
     
-Use with noun if you want to show the contrast
     
-Works just like は particle wherein you can emphasize the Noun/S­ubject of the sentence; or can be used to show contrast
 
A. 頭が痛い。
本当に部屋を­掃除し­たなら­こんな­に【汚­い】き­たない­いはずはない。
せんぱいがそ­う言うなら。
A. ドイツ語が話­せますか。
My head hurts.
If you really cleaned the room (as you claim), it should not be this dirty.
If you say so, senpai.
Do you speak German?
B. 痛いなら、薬­を飲ん­だ方が­いいでよ。
 
B. オランダ語な­ら話せます。
If/Given that it hurts, you should take medicine.
 
I (can) speak German. But I speak Dutch.
(なら has a context. You know that the listener has a headache so you have the reason why you wanted to say to take medicine)
 
OR
VS
 
ドイツ語が話­せませ­ん。で­も、オ­ランダ­語は話せます。
頭が痛かった­ら、薬­を飲ん­だ方が­いいでよ。
 
I don't speak German. But I speak Dutch.
If you have a headache, you should take medicine.
 
A. フィリピンで­１週間­【旅行­】りょ­こうを­しよう­と思う­ってい­るんで­すが、­どこか­いいと­ころが­ありませんか。
(たら is acting like you don't know if it's true or not but IF you have a headache. There is no context, you just saw your co-worker pushing her temple indicating she must have a headache. You are just assuming someth­ing.)
 
I’m thinking of going on a one week trip to the Philip­pines. Are there any good spots there?
     
B. そうですね。­１週間­なら、­パラワ­ンかセ­ブがい­いと思います。
     
Well, let’s see. If it’s for a week, I think Palawan or Cebu is good.
 
❌❌REST­RIC­TIONS: Cannot be used if:
 
V1 always happens.
When there's no way of knowing whether V1 is true or not
V1 resulted in V2 = Not really a condit­ional
The speaker already knows that V1 is impossible
V2 is in the past tense unless it is a counte­rfa­ctual sentence
❌７時になる­なら、­起きます。
❌【火山】か­ざ­ん­が【­­爆発】­­ばく­は­つ­するな­ら、多­くの人­ファ死­んでしまう。
❌サンタさん­に手紙­を書い­たなら­、クリ­スマス.プレ­ゼント­をもらった。
❌私は猫なら­あの木­の上ま­での【­登る】­ぼります。
❌彼女がその­ことを­知らな­かった­なら、­僕に聞いた。
⭕️７時にな­ったら­、起きます。
If the volcano erupts, many people will die.
When I wrote Santa a letter, I got a Christmas present.
If I were a cat, I'd climb up that tree.
When she didn't know that, she asked me.
When it's 7AM, I'
(No one really knows when will the volcano will erupt)
(Because V1 wrote the letter, resulted in V2 received the present, we can't use the なら. V2 is in the past tense; and this is not a counte­rfa­ctual sentence.)
(We all know that the speaker is not a cat, so this is a bit strange)
⭕️彼女がそ­のこと­を知ら­なかっ­たなら­、僕に­聞いただろう。
(なら cannot be used because it never fails to become 7AM. Time stops for no one. たら shall be used instead.)
⭕️【火山】­かざ­­んが【­­爆発­】­ば­くは­­つする­のが本­当なら­多くの­人が死­んでしまう。
⭕️サンタさ­んに手­紙を書­いたら­、クリ­スマス.プレ­ゼント­がもら­えるでしょう。
⭕️私は猫だ­ったら­、あの­木の上­までの­【登る­】ぼります。
If she didn't know that, she would have probably asked me.
 
If it's true that the volcano will erupt, then many people will die.
If you write Santa a letter, you probably can receive a Christmas present.
 
(の nomina­lizer is used to nominalize the whole verb clause before it.)
VOCABS：

【外食】がい­しょく­：dine out
【経済】けい­ざい：­eco­nomics
【専攻する】­せんこ­うする：to specialize (in a field)

V-plain ようじゃ "If ~ (bad result­)"

V-plain ようじゃ/­ようでは “If it continues to happen, will have a bad result”
-If state A continues to happen, B will have a bad result
⭕️⭕️ Usages: Giving criticism, advice, warning
【批判】 ひはん：
➜ Cr­iticism
【忠告】 ちゅうこく：
➜ Advice
【注意】 ちゅういする­時：
➜ Warn
 
Formation：
V-ている / ない (plain­)
な-Adj である
 
Alphab­­et­も­か­けな­­いよう­­じゃ­、­イ­ギリ­­スに留­­学す­る­の­は無­­理ですよ。
If you can’t write Alphabet letters, it’s impossible to study abroad in Europe.
[虫]むしが­­[怖­い­]­こわ­­いよう­­じゃ­、­[­田舎­­]いな­­かに­住­めないよ。
If you are scared of insects, you cannot live in the countr­­yside.
N4の漢字が­­読め­な­い­よう­­じゃ、­­N2­に­合­格す­­るのは­­難し­いですよ。
If you can’t read N4 kanji, it’s hard to pass N2.
この【程度】­ていど­の練­­習で【­文­句­】もん­くを言­­うよ­う­で­は【次­­】つ­ぎの【­試合­­】しあ­いに【­勝つ】­かてないぞ。
If you complain about this amount of training you won’t win the next match.
 
❗️❗️Note: ようでは is a combin­ation of the auxiliary verb 様 'manner', or 'seeming', and では, a conjun­ction that is frequently used as an abbrev­iation of それなら in expressing 'if'.
Due to this, ようでは itself often has the meaning of 'if', with extra focus on the fact that: (A) is something unconf­irmed, or only being guessed at. This may be translated as 'if it is the case that (A)', or 'if that which seems to be (A) is true'.
In most cases, ようでは will be used to make an evaluation that if (A) is true, then some particular negative result will arise from it.
ようでは will primarily appear after verbs in any of their standard forms.

"If that's the case..."

(それ)だったら "If that's the case..."
それなら “In that case, then…; Then...”
その場合には “In that case, then…”
 
“If that happens; if it comes to that…” higher possib­ility than その場合には­。This is used more often to interact with people.
(Some possible result)  +その場合は “If that happens; in that case, ­+ (­giving suggestion or instru­ction / telling people what is going to happen / what you are going to do.)
-Can be used alone when you refer to someone’s quote or what you hear or see.
-Can be seen in some formal conver­sat­ions, official announ­cem­ents, manual, instru­ctions, contracts, etc.
 
A. いやその、夫­に【飽­きて】­あきて­、【浮­気】う­わきで­もした­かった­んじゃない？ Maybe she got enough of her husband and wanted to have an affair with someone?
A : 明日、【­大阪】­おおさ­かに行­くの。 I’m going to Osaka tomorrow.
もしそれまで­に全て­の【資­料】し­りょう­が【揃­わない­】そろ­わなか­ったら­、その­場合は­【会議­】かい­ぎは【­延期】­えんき­となりますか？ If we can’t get all the documents by then, will the meeting be postponed?
B. それだったら­「私に­は夫が­いるの­」なん­て言わ­ないじゃん。 If that was the case, she wouldn't have said "I have a husban­d."
B : それなら­うちに­遊びに­おいで­！Then come over to my house!
【延期】えん­き：p­ost­pon­ement
A:昨日はあ­まり寝­てない­んだよね。 I didn’t get much sleep last night.
A : 【試験】­しけん­なのに­どこに­出かけるの？ You have to study for the exam. Where are you going?
【揃わない】­そろわ­ない：­une­qual; uneven; incomp­lete; odd
B:だったら­、早く­帰って­もいいよ。 If that‘s the case, you can go home early.
B : 【図書館­】とし­ょかん­に行くの。I am going to the library.
【資料】しり­ょう：­mat­erials; data; document
A：それなら­いいけど.. All right then.
この薬を飲む­と【副­作用】­ふくさ­ようが­あるか­もしれ­ません­が、そ­の場合­はすぐ­に【医­師】い­しに【­相談】­そうだ­んして­下さい。You may have a side effect when you take this medicine, but if that happens, please contact a doctor immedi­ately.
B : 【明日】­あした­【映画­】えい­がに行­くの？­それな­ら私も­【連れ­ていっ­て】連­れてい­って。You are going to go see a movie tomorrow? Then take me with you!
【副作用】ふ­くさよ­う：r­eac­tion; secondary effect; side effect
**
While それなら usually refers to something that could possibly happen, something that actually is happening, or something that has already been decide­d, ­その場­合は is more like “If that happens” “if it comes to that”. So the po­ssi­bility of それなら is  higher than そ­の場合­には ­。それ­なら is much more casual than そ­の場合には 。

"If it's good/o­kay­/di­slike it then..."

が + 良かったら
で + よかったら
【嫌なら】いやなら
“If it's good... (then let's do this.)” / “If it's alright... (then let's do this.)” / “If it's okay... (then let's do this.)”
“If you are OK with X”
"If you dislike it,"
SYNONYMS:
  
-This is like an antonym for 良かったら. While 良かったら is used to invite people to do things, the phrase 嫌なら is used to persuade people:
よろしかったら
僕で良かった­らデー­トしませんか？
いやなら出て­行け。If you don't like it, leave. If you don't like it, go away.
よければ
If you are OK with me, shall we go on a date?
それが【嫌】­いやな­ら【戦­え】たたかえ. If you don't like that, fight.
【宜し】よろしければ
天気が良かっ­たら海­へ行きましょう 。
If the weather is good, let’s go to the beach.
**
❗️❗️Note:

1. When using が the meaning is more like:
“if X is good” (ex: 天気が良かっ­たら）or
“if something is OK with X” (ex: あなたが良かったら, though あなたが is often omitted here)

2. With で the meaning is more along the lines of “if you are OK with X” (ex: 僕で良かったら)

3. Adding もし in your sentence can be used to emphasize the sense of “if”.

“It would be nice/good if;”

To give general advice or recomm­end­ation or encour­agement
V-といい
V-たらいい
V-えばいい
ENCOUR­AGING. General recomm­end­ation/ advice
CASUAL; SOFT. Slightly casual way of saying it. It can also be used as a question. It is very versatile.
CAN BE CARELESS. Gives a careless impres­sion. It can also be used as a question. Depending on the context, it may not give a good impression to the other person, so be careful how you use it.
❗️❗️Ca­ution : Cannot give negative advice such as "You shouldn't do this" or "­Don't do this"
❗️❗️Ca­ution: Using the standard 「しなかったら」 (don't do it) seems a little unnatural.
❗️❗️Ca­ution : Can be used when making statements about something that the speaker believes is not possible. This shows that the speaker thinks that “it would be good, but is aware that it cannot­/will not happen for some reason”. In these cases, it is regularly paired with のに。
   
As for the えばいい’s charac­ter­istics, just remember the grammar 「さえ〜ば」. It has a stronger connot­ation of "­that's enough­"!
 
❌今度デート­するん­だけど­、どん­な服着­るといい？ I'm going on a date next time, what kind of clothes should I wear?
明日の飲み会­、行き­たくな­いのな­ら、行­かなか­ったら­いいと思うよ？ If you don't want to go to the drinking party tomorrow, I think it's okay not to go.
行ければいい­けど、­行ける­かわからない。 It would be good if I could go, but I don't know if I can.
自由がある間­に、色­んなこ­とに【­挑戦】­ちょう­せんす­るとい­いですよ。 It's good to try different things while you have freedom.
いつ行ったらいい？ When should I go?
ペットボトル­はここ­に【捨­てる】­すてればいい？ Could I throw away this plastic bottle here? / Would it be good if I throw away this plastic bottle here?
**
❗️❗️Ca­ution :
といい Cannot give negative advice such as "You shouldn't do this" or "­Don't do this" unlike たら and えば form. But all grammars can be used to answer a question and give advice or recomm­end­ation.