What is “grammar” in this sentence?

I am a bit confused about whether “grammar” is an indirect object or a noun. What is the word class of this word

My students rightly expect me to research my grammar before I deliver the lesson.

My = adjective
rightly = adverb

me = object

to= preposition
research = verb
grammar = ??????
deliver = verb
the = definite article

Answer

“Grammar” is the direct object of the verb “research”. It’s also a noun.

(Subjects, direct objects, and indirect objects are almost always nouns.)

Attribution
Source : Link , Question Author : Safi Moussa , Answer Author : Stephen Dunscombe