(MODAL) (用于疑问句时,can 表示礼貌的请求,而 can't 表示强烈请求) You use can in questions in order to make polite requests. You use can't in questions in order to request strongly that someone does something.
● Can I have a look at that?...
我能不能看一眼那个?
● Can you please help?...
请你帮个忙好吗?
⑥ (MODAL) (表示允许)可以 You use can to indicate that someone is allowed to do something. You use cannot or can't to indicate that someone is not allowed to do something.
● You must buy the credit life insurance before you can buy the disability insurance...
所以,之前的小女孩说的
CAN I watch TV 本来就是对的,而且表示征求允许这种用法在口语中can用的比May更多。