The modal verb 可以
In Chinese, 可以 (kěyǐ) stands before a verb and expresses possibility, ability or permission.
In English it is usually rendered as “can” or “may”.
Basic structure
Subject + 可以 + verb
Meaning:
someone may do something.
我可以再问您一个问题吗？
我wǒI
可以kěyǐmay / is it allowed
再zàiagain
问您一个问题wèn nín yí ge wèntíask you one question
吗maquestion particle
Here 可以 is used to ask permission.
你们可以看这本书
你们nǐmenyou
可以kěyǐcan
看这本书kàn zhè běn shūread this book
Here 可以 states that something is possible.
我可以坐吗？
可以，请坐！
可以 + 坐
may + sit
Here 可以 both asks for permission and grants it.
The rule in short
可以 + verb
Meaning:
it expresses possibility, ability or permission.
Examples:
我可以再问您一个问题吗？
你们可以看这本书
我可以坐吗？