Modals of ability are used to describe the different skills, talents, or gifts we have. The Modals that we use are Can, and Could.
Affirmative
Subject + Modal + Base verb + Complement.
I can dance.
She can bake cakes.
We can work from home today.
Negative
Subject + Modal + Not + Base verb + Complement.
Note: Sometimes we use the negative with a contraction, can not "can't"
I can not work today.
We can't see you yet.
They can't have the car today.
Yes and No Questions
Modal + Subject + Base verb + Complement?
Can you give me some more sugar?
Can you come home early?
Can you help me with this?
Wh Questions
Wh + Modal + Subject + Base verb + Complement?
When can you help me today?
What can you do today?
Who can she see today?
We use could in the same way that we use can, but in this case, it is for past abilities.
Affirmative
Subject + Modal + Base verb + Complement.
I could travel more when I was single.
We could eat more when we were young.
She could only do a few assignments while on vacation.