The suggestions you have received are good ones. "Doing" a degree is commonly used, but that use of "do" is very informal. One could say one is pursuing/earning/working toward/ a degree in English. Of course, I am studying English works too.
Is the correct pronunciation the dog lay down or the dog layed down?
This verb is a constant problem. The transitive verb (lay something) is lay/laid (present/past). The intransitive verb (lie) is lie/lay (present/past).
I am studying English, would you say that it is appropriate to call some English bad and some good? :roll:

:roll:
There are different levels of English. Standard English is considered by most to be the most correct. There is also informal English, which is acceptable in most speech and in informal writing. It contains some slang and there is some relaxing of grammar rules. There are also levels of English that are characterized by much slang and poor grammar. That English is bad, in my opinion. One of the problems with poor English is that it can become a habit. When that happens, it can be difficult to switch to correct English when it is needed. :wink: