Could / Couldn't (A1)

Use could + o verbo no infinitivo para algo que você conseguia fazer no passado. Sem to depois de could: I could swim, e não I could to swim.

could + verbo no infinitivo

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.". Não coloque to entre could e o verbo.
Experimente: Yasmin: Was Mateo good at sports? Lani: Yes, he ___ soccer very well at ten. Complete o que a Lani diz. (could play / could to play / could playing) Resposta: could play — A Yasmin pergunta com Was, e at ten já passou, então é uma habilidade no passado. Depois de could, o verbo fica no infinitivo — sem to e sem -ing.

could nunca muda. He, she, it também usam could, e o verbo depois dele não leva -s.

I could speak English.
She could speak English.
They could speak English.
Not "She could speaks English." — say "She could speak English.". Mesmo com she, o verbo fica no infinitivo, nunca could speaks.
Experimente: Ethan: Was Sofia good at languages? Camila: Yes, she ___ two languages at ten. Complete o que a Camila diz. (could speak / could speaks / coulds speak) Resposta: could speak — Could nunca muda, e o verbo depois dele nunca leva -s, nem com she. E também não existe "coulds".

Para algo que você não conseguia fazer, use couldn't + o verbo no infinitivo. (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.". Depois de couldn't, o verbo fica no infinitivo: find, não found.
Experimente: Camila: Why were you outside so long? Hiroshi: It was dark. I ___ the number on the door. Complete o que o Hiroshi diz. (couldn't see / couldn't saw / don't see) Resposta: couldn't see — O Hiroshi diz It was dark, então ele está falando de um momento que já passou. Depois de couldn't, o verbo fica no infinitivo — see, não saw — e don't see fala de agora.

Para perguntar, coloque Could antes da pessoa, e depois o verbo no infinitivo.

Could you swim at five?
Could she speak French?
What could you do?
Not "Did you could swim?" — say "Could you swim?". Numa pergunta, Could vem primeiro; você não precisa de 'did'.
Experimente: Matilda: ___ you cook when you were young? Lars: Only eggs! Complete o que a Matilda pergunta. (Could / Did could / Were) Resposta: Could — When you were young coloca isso no passado, e numa pergunta no passado Could vem antes da pessoa — você não coloca did na frente.

Juntando tudo: depois de could, o verbo nunca muda — sem to, sem -ing, sem -s e nunca numa forma do passado.

She could cook at twelve.
We could walk to school.
They could read music.
Not "She could cooked at twelve." — say "She could cook at twelve.". Depois de could, o verbo nunca muda — nem -ed, nem -ing, nem -s.
Experimente: Sofia: Were you a fast child? Lani: Very! I ___ all the way home when I was five. Complete o que a Lani diz. (could run / could ran / could to run) Resposta: could run — A Sofia pergunta com Were e a Lani diz when I was five, então é passado. Depois de could, o verbo nunca muda: run, não ran, e sem to.

Você já conhece could para habilidade no passado. Could you...? também é um jeito educado de pedir algo agora.

Could you help me, please?
Could you open the window?
Could you say that again?
Experimente: Matilda: Could you take this bag? My hands are full. Ethan: ___ Escolha o que o Ethan diz. (Of course. Here, give it to me. / Yes, I could. I was strong then. / No, I couldn't find it.) Resposta: Of course. Here, give it to me. — As mãos da Matilda estão ocupadas agora, então ela está pedindo ajuda, não perguntando sobre o passado. Uma resposta sobre o que o Ethan conseguia fazer antigamente, ou sobre encontrar alguma coisa, não combina.

Incorreto	Correto	Por quê
She could to swim.	She could swim.	Não coloque to entre could e o verbo.
She could speaks English.	She could speak English.	Mesmo com she, o verbo fica no infinitivo, nunca could speaks.
She couldn't found her keys.	She couldn't find her keys.	Depois de couldn't, o verbo fica no infinitivo: find, não found.
Did you could swim?	Could you swim?	Numa pergunta, Could vem primeiro; você não precisa de 'did'.
She could cooked at twelve.	She could cook at twelve.	Depois de could, o verbo nunca muda — nem -ed, nem -ing, nem -s.