单词This is anegg That is Tom It is adesk Those are变为否定句一般疑问句肯

This is not an egg。Is this an egg?Yes,this is。No,this isn't。That is not Tom。Is that Tom?Yes,that is。No,that isn't。It is not a desk。Is it a desk?Yes,it is。No,it isn't。否定句的变法：：（1）若句中有系动词（am,is,are)的,直接在后面加not（2）若句中没有系动词的 在动词后面直接加not。一般疑问句的变法：（1）若句中有系动词（am,is,are)的,直接将系动词提前,再将主动词,既实意动词变为一般形式,例如：My name is Gim Tadder 变为一般疑问句既是：Is your name Gim Tadder?（2）若句中没有系动词的,在句前家do,例如：I like reading books。变为 Do you like reading books?希望能够帮到楼主