Question

What word in this sentence modifys always.
Enrique always keeps the members of the swim team in stitches.

Answer 1

No word in that sentence modifies "always". In order to modify "always", a word would limit or further contribute to the meaning of "always" in that sentence. However, nothing in the sentence gives any indication that "always" is to mean anything other than its normal definition.

An example of a word that could modify "always" is "almost", as in "Enrique almost always keeps the members of the swim team in stitches, except for when he showed up late the day of the swim meet and everyone was furious with him."

I wonder if maybe your question was supposed to be "What word does 'always' modify?"