grammaticality - Tense choice problem

I have to go to sleep because I have a class [-----] at 7:30 A.M.

In the above sentence, which of the following fits correctly in the blank, and why?

• begin


• begins



• is beginning


• began

Answer

None of the above are strictly correct. A proper construction would be the following:

I have to go to sleep because I have a class that begins at 7:30 A.M.

(Note you could also say "which begins" instead of "that begins"; either is fine.)

To explain why, let's deconstruct the sentence. We begin with the simplest part:

I have to go to sleep.

That's fine as a sentence on its own, but raises the question of why you have to go to sleep. The answer is "because you have a class." So we build on the construction:

I have to go to sleep because I have a class.

Now the author of the sentence wants to add more to the sentence; they want to describe that class. You must sleep because you have a class; what kind of class do you have? A class that begins at 7:30 am. And now we've arrived at the complete construction:

I have to go to sleep because I have a class that begins at 7:30 A.M.