Could / Couldn't (A1)

Используй could + глагол в базовой форме для того, что ты умел делать в прошлом. Без to после could: I could swim, а не I could to swim.

could + глагол в базовой форме

When Amina was five, she could swim.
Hiroshi could ride a bike at six.
I could read when I was four.
Not "She could to swim." — say "She could swim.". Между could и глаголом ничего не встаёт, никакого to.
Попробуйте: When Amina was five, she ___. (could swim / could to swim / could swimming) Ответ: could swim — После could используй глагол в базовой форме сам по себе: could swim. Без "to" и без "-ing" после could.

could никогда не меняется. He, she, it тоже используют could, и глагол после него без -s.

I could speak English.
She could speak English.
They could speak English.
Not "She could speaks English." — say "She could speak English.". Даже с she глагол остаётся в базовой форме, никогда could speaks.
Попробуйте: When she was young, Sofia ___ French. (could speak / could speaks / coulds speak) Ответ: could speak — Could никогда не берёт -s, и глагол после него тоже остаётся в базовой форме: could speak (не "could speaks" и не "coulds").

Для того, что ты не умел делать, используй couldn't + глагол в базовой форме. (couldn't = could not.)

She couldn't find her keys.
I couldn't swim when I was three.
They couldn't come yesterday.
Not "She couldn't found her keys." — say "She couldn't find her keys.". После couldn't глагол в базовой форме — find, а не found.
Попробуйте: Hiroshi ___ his keys this morning. (couldn't find / couldn't found / didn't could find) Ответ: couldn't find — Отрицание — это couldn't + глагол в базовой форме: couldn't find (не "couldn't found" и не "didn't could").

Чтобы спросить, поставь Could перед человеком, а потом глагол в базовой форме.

Could you swim at five?
Could she speak French?
What could you do?
Not "Did you could swim?" — say "Could you swim?". Для вопроса Could идёт первым, 'did' тут не нужен.
Попробуйте: ___ you ride a bike when you were six? (Could / Did could / Were) Ответ: Could — Начни вопрос с Could, перед человеком: Could you ride a bike? Перед could «did» не добавляй.
Попробуйте: Remember what follows could, As a child, Lani ___ a bike. (could ride / could rides / could to ride) Ответ: could ride — После could всегда глагол в базовой форме: could ride. (Без -s, без "to", без "-ing", каждый раз.)