When you are speaking I advise u not to care for grammar because if you care, u won't speak faster, you will speak and think of grammar and that makes you not to speak good. just think of grammar when you are writing.

I appreciate it so much

How much money is correct

If you want to improve your writing, you should feel what you are writing. Because feeling makes a great writing of story or article

The correct answer is (Is /are) Because (the students) is one group (singular) But the second is plural because the students are more than one or more than one group. It is unknown. In general when we have (the) before nouns we it means singular but when we have (a) before nouns it means plural.