English~~~

She hasn't a good time at party
改为She hasn't had a good time at party
在使用否定句时应加助动词do、does 因为这个句子是现在完成时，所以后面的动词用过去时
is your friend come from Canada? 有be from 和 come from 所以应把is 改为Does
the students don't their homework on Saturdays 此问题和第一个一样，应为the students don't do their homework on Saturdays
Sometimes i am helping my mother with the homework Sometimes应用一般现在时而不是现在进行时，应改为Sometimes I help my mother with the homework

第一句就是上面那个的回答.第2句应该是The student don't do their homework on Saturday.
第3句的意思都不对，它的意思是：有时我帮我妈妈做作业．很奇怪吧．可能是有是我妈妈辅导我的作业：Sometimes my mother heips me do my homework.
最后一句：Is your friend comes from Canada?(第3人称单数要加S）