以下所有英文句子看一下哪些语法有错或者单词有错?Cat is on the desk,Cat is not on the desk ,Book is in the bag,Book is not in the bag,Cat is so big,Cat is not so big,These are many pen,These are not many pen

一般会说the cat is on the desk,cat 前面会加个冠词的。book前也要冠词。
或者你用there be句型，更常见点。there is a cat on the dest./there is a book in the bag/
there are many pens.有many了，pen要变复数，然后是there，不是these.后面也一样

These are many pen 很少这样写啊，一般There are many pens .pen要用复数

A cat is on the desk.(The cat is on the desk.)
The cat is not on the desk.
The book is in the bag.
The book is not in the bag.
The cat is so big.
The cat is not so big.
These are many pens.
These are not many pens.

最明显的是：These are many pen_s.
These are not any pens.