I (can't/couldn't) play the piano when I was younger.
couldn't
Can/Do I borrow a pen?
Can
Sheryl (knew/knows) how to paint before, but she doesn't know now.
knew
Yes, I (was/am) able to run five miles.
am
To your boss: (Can/Would) you help me with this project?
Would
Where (are/is) you going?
are
Who (is/are) she talking to?
is
She (were/was) riding her bike when she saw an accident.
was
He (break/broke) his phone while he was traveling.
broke
(Can/Could) you spell "Massachusetts" when you were in fifth grade?
Could
Do you (know/knows) when the show begins?
know
To your brother or sister: (May/Can) I use your phone?
Can
