Can

verb

1. (auxiliary verb, defective) To know how to; to be able to.

   "She can speak English, French, and German.   I can play football.   Can you remember your fifth birthday?"

2. (modal auxiliary verb, defective) May; to be permitted or enabled to.

   "You can go outside and play when you're finished with your homework.   Can I use your pen?"

3. (modal auxiliary verb, defective) To have the potential to; be possible.

   "Animals can experience emotions."

4. (auxiliary verb, defective) Used with verbs of perception.

   "Can you hear that?."

5. To know.