Because they can see if you are struggling or doing well with subjects. They also learn things from helping you.
Finish your homework.
Yes the want you to do your homework.
Tarea is assignment .... and typically used to mean homework assignment by the parents in my school.
"I forgot to do my homework. I know I should do extra homework so I can learn how to punctuate and capitalize a sentence."
Homework is supposed to be for the child to help them learn the material better.
Too many - children are supposed to do their own homework to help them learn, but there are parents who want to help their kids get better grades so they will do the homework for them. In the long run, however, these parents are selling their children short by not allowing them to learn on their own.
the parents are always worried about them
Mind your parents and do your homework.
You don't. Your parents know that if you do not do your own homework, you won't learn what you should be learning. They'll want you to do it yourself, but if you get stuck on something, they will probably be happy to help you.
because it is important
It depends on how firm the adults are that you are trying to convince that you should not have homework. Usually, if homework is assigned parents and teachers alike are firm that you do it and they will not be talked out of it.
One constrant is that some students' parents may not value homework or might be at work when kids are doing their homework. That would leave some students without a way to get the assignment done.