he's doing homework改为一般疑问句 l like chicken.改为否定句

疑问句,be动词is提前到句首：Is he doing homewrk?
否定句,动词like前加do not：I don't like chicken.
否定句,be动词are后面加not：There aren’t three parrots in the tree.
缩写形式：do not=don't
are not=aren’t