1.the students at this school are mainly from the countryside.

1.the students at this school are mainly from the countryside.
请问此句中的mainly为什么要用副词形式,main形容词形式不行吗?
2.you stand there feeling like everyone is looking at you,译这个句子,另分析下这个句子,四个动词,看不懂
3.today we had an English test,we have a monthly test on each subject .请问 monthly 此处是形容词吧?那on each subject 中的on怎么译?
4.to me ,learning foreign languages is really fun ,请问 fun 此处是形容词吧,它也做名词怎样区分呢?另to me开头这叫什么语法?能变成这样吗:learning foreign languages is really fun for me.
5.always look through your work before handing it in .请问这句的主语是谁?