Modal verbs

Can / Can't

Use it for present ability, possibility, or permission.

Rule

After can/can not, use the base verb without to. It does not change by subject (no -s) and does not need do/does.

Formula

Positive (+)Subject + can + V1I can swim.She can drive.
Negative (-)Subject + can't / cannot + V1You can't smoke here.He cannot lift that.
Question (?)Can + subject + V1?Can you help me?Can she cook?

Notes

  • Cannot is the full form; can't is the short form
  • It does not change: I can / he can (no -s)
  • No do/does in questions
  • Request: Can you...? = asking someone to do something