Commas before connectives?

[InterruptingCow]

DS1 (year 3) is being taught connectives at the moment and is being told that he must put a comma before the connective. For example, "I like cake, but my brother likes chocolate." This is wrong, surely? Have the rules changed since I went to school (admittedly a long time ago!!).

I think if both statements are a sentence in their own right i.e I like cake. My brother likes chocolate. Then I'd expect it to be either a comma or a but - certainly not both.

hmmm - any school teachers around I wonder?

If the two parts of the sentence could be free standing sentences on their own, (like the cake and chocolate example) then yes, it's correct to put a comma before the conjunction. Not otherwise. (I think!)

I would use the comma.

x-posted.
I'm an English lang teacher, but tbh, never teach conjunctions.

hah! but see ^ that sentence up there, comma before but....hmm.

You CAN use commas with 'but' and probably should do unless the part following the but is fairly short.
....................

I like eating cake and biscuits, but the delights of eating a croissant are the most wonderful.

I like your brother but not you.

I suppose a comma is merely a pause for the writer/speaker to go in a different direction.

So in your case OP perhaps comma and but do go together.

Not saying you would OP, but I wouldn't like to contradict what your dc's school are teaching though - unless it was particularly harmful to dc's education.

Aaah, I put a comma before the but...

Hmm. I usually teach that if the main clause comes first in a complex sentence, then you don't need a comma. Whereas if the sentence begins with a subordinate clause, you need the comma before the main clause.

Disclaimer This is just to give my pupils a clear 'rule' to follow while they get to grips with 'a variety of sentence structures'. I know it's more complicated than this in 'real life' though

Hmmm...I tend to go with the oxford comma

The oxford comma is something different, to do with lists rather than separating sentence elements.

I think this use of commas is an example of when punctuation was used in the long distant past as an aid to someone reading the text out loud, to indicate pauses or when to take a breath (much like in written music), and in more recent times to delineate parts of the sentence either for emphasis or disambiguation when reading the text to oneself.

I'd suggest going along with what the teacher says, but mention to your DS that these are guidelines rather than rules. If there's one thing to be said about the English language it's that for every 'rule' there's almost always an exception.

yes, there's a comma.

like someone else said, if it stands as two separate sentences, there's a comma.

I like ice cream, but my brother likes cake.
I like ice-cream and cake.
I like ice-cream but not cake.