frases com could e study com os pronomes I, you, he, she, it,...

I couldn’t do nothing
She couldn’t go to class because she was sick
They couldn’t stop the car
He couldn’t go to the meeting because he went to the doctor
You couldn’t help him even if you wanted to
I couldn’t do it

Could you study science with me after class?
Could you help her?
Could you go to the store?
Could I have it?
(To sem ideia pra mais interrogativas)​