Translation:It is my book.
Can I not use ce est instead of c'est?
No, in French, unlike English, the contractions are mandatory.
I would swear she said 'fait' instead of cest'
Why are there two "its" instead of one?
c'est = it is.
mon livre = my book.
There is only one it
Why was "this is my book" not accepted?
I've definitely learnt livre before.