たら
When/if X has happened, Y is true
Verbs: Past tense + ら, Y
い Adjectives: Past tense + ら, Y
Nouns/な Adjectives: だったら/でしたら
たら means when or if. For the most part, you may think of たら as “When X has happened“. This “when” is a supposition, and the event may or may not occur.
As a conditional, たら has the broadest usages, so this is what you should use most of the time.
It tends to place more emphasis on the result than the action itself.
The たら clause is completed before the statement after it. (Same as English if, see red below).
Verbs and い Adjective Examples
- 食べたら行きます – When (it) has been eaten, I will go.
- 先生に聞いたらわかる – When you have asked the teacher, you will understand. (i.e. not when you ask)
- 家に帰ったら電話して – Give me a call when you have gotten home. (when going home is finished)
- 走ったら、水をたくさん飲みます – I drink a lot of water when I have ran. (If I run).
- なぐられたら、おこってはいけない – If/When you have gotten punched, It’s not good to get mad.
い Adjectives conjugate identically to verbs, by adding ら to the past tense.
- やさしかったら、なかない。- Won’t cry if/when you are nice.
- にがかったらゆるさないよ – I won’t forgive you if its bitter.
Nouns and な Adjectives
With a noun (だったら/でしたら）, たら means “If/when the case is X” This makes it functionally identical to なら.
- 猫だったら安心だ – If it is/was a cat, that’s good
- 熊だったらどうする – If it’s a bear I don’t know what to do.
- しずかだったら寝られる – I can sleep if/when It’s quiet.
たらどうだ
How about you do X?
Verbたら+どうだ？
たら can be used with どう (How’s is it) to give advice. たらどうだ？ means “When X has been done, how’s that” →”How about you do X”
You should be careful when using this pattern, as unsolicited advice could come across as rude. The どうだ may be dropped.
- 花をあげったらどうだ？- How about if you gave flowers?
- 食べてみたらどうだ？- How about you try eating it?
- もう帰ったら？- How about you go home. (Possibly: How about you just go home already)
- がんばったらどうだ？ – How about you try? (Rude)
With the Past Tense
When X, Y
たら + Past tense
たら can be used in the past tense, to indicate something happened when you did something else, kind of like 時. It implies causation. This たら may also mean “While” with progressive tense words.
- 本を読んでいたら, 眠くなった – When (While) I was reading a book, I got sleepy.
- 彼を聞いたら、怒った – I got mad when I listened to him.
Surprise
たら + Past tense may also be used to indicate an unexpected occurrence. This doesn’t need to be a jump out of your socks surprise, a small one will do.
- ドアを開けたら、世界が変わった – When I opened the door, the world changed.
- 学校に行ったら、誰もいなかった – When I went to school, no one was there.
- 引き出しを開けたら、くもが出てきた – When I opened the drawer, a spider came out.
- 泳いでいたら、いつの間にか日が沈んだ – When(while) I was swimming, the sun set before I knew it.
Note about たら
Although alluded to above, たら is formed from the past tense, which is also the completion tense, the tense for things that have already finished. たら should be thought of as this tense, and not just past tense. This is why I listed たら’s meaning as “When X has happened/completed”. If you keep this meaning of completion in mind when reading たら, most meanings should become self apparent.
References/Further Reading
This was a pretty annoying one to explain concisely, and I will likely redo this topic in the future. Here are some references that you may use for additional reading on the topic.
References:
Coelang (Japanese)
Tae Kim
TomoJuku (Japanese)