when do I need 的?

[BeNe]

I started to learn a bit mandarin, and I have a question on the possesive word 的. In one sentence I read: 这是我爸爸 (without 的), another sentence said: 我的课本在家 (with 的)
what is the rule?

 

[Minty]

这是我爸爸 (without 的)

In this sentence you can also add the 的, it becomes 这是我的爸爸 .

Another sentence said: 我的课本在家 (with 的).

With non human nouns like your dog, his cat,her flower you have to use the possessive particle 的. But with human nouns like dad, mum, aunt, sister, brother you can omit the 的 but you can also use the 的.

 

[BeNe]

ok, i thought that there is something with human beings 谢谢！