After school, I go to an afterschool class to study math.
(Is this a correct sentence? Do you ahve better expressions?)
Since you've used "after school" twice, this would be better:
After school I go to a math class.
or:
I take an after-school math class.
Thank you.
Then can we say:
My favorite class is a math class.
Yes, we can say that.
However, as I said before, it's more common to say: My favorite class is math class.
However, if you are taking two math classes, it's more accurate to say which math class is your favorite.
Example: My favorite class is algebra.
Yes, your sentence is grammatically correct. However, if you're looking for alternative expressions, here are a few options:
1. "I attend an afterschool math class."
2. "I take part in a math study program after school."
3. "After school, I go to a class where I focus on math."
Remember, the choice of expression depends on your personal preference and the context in which you are using it.