I could see it going down the drain.
In this sentence, I want to ask whether "going" is a gerund or "going down" is a phrasal verb.
And is the word "see" modifying "it" or is "going" modifying "it"? Please explain properly because I am a novice.
I see X. X is the object of see. x = "it going down the drain" is a clause that serves as the object of the sentence.
Separately, if we look at the sentence this clause would be based on: "It is going down the drain", we see that "is going" is the verb, and "down the drain" is the object clause "Where is it going? Down the drain."
Putting everything together:
"I see [it going (down the drain)]."