Hi,
In this sentence, besides is being used as an adverb because the verb isn’t in the ing form. At least that’s the rule in English. When we have a preposition and it’s followed by a verb it has to be in the ing form.
I was trying to understand why it’s an adverb and not a preposition.
“Did you do anything besides sit on the couch?”
I’d call it a preposition. I don’t see why it matters whether the verb is in the ‘ing’ form or not.
Does it matter what part of speech it is? Many parts of speech are pretty fuzzy, especially adverbs. You always get in trouble when you try to put things in nice neat categories. As soon as you think you have enough categories, you find something that doesn’t fit well in any of them.
I teach ESL here in Brazil, so this got me confused because I’d write “sitting” instead of “sit” and would correct a student if he or she had written “sit”. This sentence is from a novel I’ve been reading. I checked besides adverb and besides preposition, but had problems to spot the difference.
I would say it’s a ‘linking adverb’ meaning ‘in addition to’ or ‘other than’.
The original sentence sounds more natural to me. “Sitting” sounds a little odd in that sentence, but not terrible.
“Sit” vs “sitting”.
I think that “sit” is a greater condemnation than “sitting”. To me, “sit” seems to represent a greater degree of inactivity.
The speaker might have said:
“Did you do anything besides sit there like a bump on a log?”
Here’s an unrelated quote:
“Sometimes I sit and I think - and sometimes I just sit.”