たらどう details
write + (past) + why don't you
kaita radou
why don't you; how about doing — a suggestion phrased as a question
meaning: why don't you write
疲れてるなら、少し休んだら？
tsukareteru nara, sukoshi yasundara?
If you're tired, why don't you rest a bit? casual
分からないなら、先生に聞いたらどう。
wakaranai nara, sensei ni kiita radou.
If you don't get it, why don't you ask the teacher? neutral
- contraction
- formal
- polite
Examples
why don't you; how about doing — a suggestion phrased as a question, leaving the choice to the listener
疲れてるなら、少し休んだら？
tsukareteru nara, sukoshi yasundara?
If you're tired, why don't you rest a bit? casual
分からないなら、先生に聞いたらどうですか。
wakaranai nara, sensei ni kiitaradoudesuka.
If you don't get it, why don't you ask the teacher? neutral
一度、専門の先生にご相談なさったらいかがですか。
ichido, senmon no sensei ni go soudan nasattara ikaga desu ka.
Why don't you consult with a specialist? formal
Formation
{V-ta}らどうattaches to た-form
Variant notes
- たら — どう drops entirely in casual speech, often on a gentle rising intonation — 一度[いちど]聞[き]いてみたら？
- たらいかがですか — いかが replaces どう for a more deferential register — service and business contexts, 一度[いちど]ご相談[そうだん]なさったらいかがですか。
Notes
full どうですか, or swapping to たらいいんじゃない — a bare falling-tone
たら reads the bluntest of the set.
Related patterns
Similar
たらどう is literally a QUESTION shape (どう？／どうですか), visibly leaving the choice with the listener — and can read passive-aggressive when the speaker is annoyed (もう謝[あやま]ったら？), never used upward; たほうがいい states the recommendation as a flat comparative fact, more direct and confident advice with no interrogative softening built in.
Lookalikes
The たら here is the ordinary conditional (行ったら), but paired with どう it fossilizes into a suggestion formula asking "how would it be if you did" — reading it as a plain conditional clause about a result misses that the whole frame performs a SUGGESTION, not a hypothesis.