I skip my classes today.

My mum came in to my room just now.

SHE:Why don't want go school?
ME :I were too tired yesterday I straight away fall asleep and forgot to set my alarm clock.
SHE:Don't I already asked you to sleep early every night?

OMGahhh..Tired will automatically sleep early right?But what the fish she asking me that way again?I don't know whether I speak not clearly,you don't know mandarin or you don't know human speaks tho?I don't know.

Conclusion:I skipped my class is because I forgot to set my alarm clock.