comma and modifying clause starting with "but"

[tomlitilia]

Am I correct that this sentence needs the comma before "but"?
"They tried to be discreet about checking me out, but only for like a second."

The clause starting with "but" isn't independent; it doesn't have it's own subject. So, usually that means the sentence shouldn't be split by a comma. But here it's a modifying clause, right? It is changing "discreet about checking me out," and if this modification had been something that didn't start with "but", I would definitely use comma punctuation, e.g. as in:
"They tried to be discreet about checking me out, looking away each time I turned around."

 

[AlinaX]

They checked you out for a second? Or were discreet for a second?
Comma before the but, sure, but what about the like?

 

[stellataylor]

I think I would just phrase the sentence a little differently, to sound a bit less awkward with the comma in there.

You could try:

"They tried to check me out discreetly, but gave up after a moment."

"They attempted to be discreet while checking me out, but then quickly looked away."

I obviously don't know the context or your character's personality, so take my opinion with a grain of salt.

 

[R. Richard]

Am I correct that this sentence needs the comma before "but"?
"They tried to be discreet about checking me out, but only for like a second."

The clause starting with "but" isn't independent; it doesn't have it's own subject. So, usually that means the sentence shouldn't be split by a comma. But here it's a modifying clause, right? It is changing "discreet about checking me out," and if this modification had been something that didn't start with "but", I would definitely use comma punctuation, e.g. as in:
"They tried to be discreet about checking me out, looking away each time I turned around."

"it's own subject" ???

 

[NotWise]

Am I correct that this sentence needs the comma before "but"?
"They tried to be discreet about checking me out, but only for like a second."

You can use commas to offset a clause that acts as a negation, which I think is happening in your sentence.

I might also avoid the question by using an em dash in place of your comma.

Did they become indiscreet after their second of discretion?

 

[KeithD]

responding to your actual question--how you'd punctuate that sentence, not how you'd rewrite in someone else's voice:

I'd put a comma before the "but," not because the second clause is independent but because it is a significant shift in the sentence. I'm on the road and can't look up supporting documentation for it, but I'd put a comma there. Also, as someone else noted, I'd set the "like" off with commas too--before and after.

 

[SamScribble]

I concur with Keith

 

[SimonDoom]

The words following "but" are not a clause because theres no subject or verb, but a non restrictive adverbial phrase that modifies the word "tried." Definitely use a comma. CMOS 6.31.