Comma before But. Always?

I always put a comma before the word but, simply because right or wrong, I understand this to be correct.

However, sometimes I don't 'hear' the pause before the 'but' in certain sentences, and find myself asking if it should be there.

Example: 'I checked the side mirror. The van was still there, but no longer seemed to be gaining.'

I'm not hearing the pause before the 'but', so should it be there or not?

 

Only at the start of an independent clause, I believe, but I'm sure if I'm wrong someone will correct me.

 

i think you and i were having much a similar conversation last night with comma placement (namely to stop me being shouted at for you not being your in the most stupid places)

I tend to put a comma in front of but if the sentence needs it (say if i feel there needs to be a minor break in the sentence, before but is a good place)

 

I'm with @obsidian_cicatrix - only at the start of an independent clause.

The "put a comma where you would take a breath" rule really isn't grammatically sound - it's better if you can figure out the actual rules.

So, for your example, no comma. But if you changed the second part to be an independent clause (something that could be a full sentence if it were on its own) you'd want the comma: The van was still there, but it no longer seemed to be gaining. (this is the same rule for the other words that work like this - conjunctions of some sort. (and, for, yet, etc.))

 

Thanks. You have quite a knack for making things understandable.

 

Yes, I agree with what BayView said.

In fiction, however, writers sometimes take liberties with such things. As a result, you could have two independent clauses connected by a conjunction with no comma. You could also have it the way shown in the original post. It's a stylistic choice, though you should be aware of why you're breaking the rules.

 

Yup, to the two clauses connected a by conjunction. I've done that a time or two. For me, it really depends on the length and cumbersomeness of the sentence. If it were to stretch to a couple of lines long, that would be a bit much to read without a break. I'd have visions of the poor reader getting frustrated by it. I would.