Quick answer
де́лать (imperfective) = doing, in progress, repeated. сде́лать (perfective) = done, finished, with a result.
Я де́лал дома́шнее зада́ние. — Я сде́лал дома́шнее зада́ние.
I was doing my homework. — I finished my homework.
де́лать
imperfective — the process
- In progress
- Repeated, habitual
- No result stated
- Has a present tense
Что ты де́лаешь?What are you doing?
сде́лать
perfective — the result
- One completed action
- The result matters
- No present tense
- Its “present” means the future
Я всё сде́лал.I have done it all.
Aspect across the tenses
| де́лать | сде́лать | |
|---|---|---|
| present | де́лаю | — (does not exist) |
| past | де́лал — was doing | сде́лал — got it done |
| future | бу́ду де́лать | сде́лаю |
| imperative | де́лай — get on with it | сде́лай — get it done |
A perfective verb has no present, because you cannot be in the middle of something that is by definition finished.
Choosing in the past
The same logic everywhere
Once this pair clicks, every other pair follows the same logic: чита́ть / прочита́ть, писа́ть / написа́ть, говори́ть / сказа́ть.
Typical mistakes
Я сде́лаю э́то ка́ждый день.
Я де́лаю э́то ка́ждый день.
Repeated action is always imperfective.
Я бу́ду сде́лать.
Я сде́лаю.
бу́ду never combines with a perfective verb.
Check yourself
Which means “I will finish the homework”?