Question about grammar

[Rodel Barnachea]

I'm hoping some of y'all know whether these errors are grammatical or ungrammatical.

1st Sentence: Sara smiled at him, but could not hold it.

I believe this is an error because the second clause ("but could not hold it" is a dependent clause, so no comma must be used before "but". Am I right in this explanation? Could this be correct when used in British English?

2nd Sentence: He caressed her gloved hand, and just wished...

I also believe that this is an error because of the same explanation I have for the 1st sentence. the second clause ("and just wished..." is a dependent clause, which means that no comma must be used before "and". Am I also correct in this explanation? And Could this sentence be correct when the style used is found in British English?

Thank you to all that will help me!

[gali]

I'm hoping some of y'all know whether these errors are grammatical or ungrammatical.

1st Sentence: Sara smiled at him, but could not hold it.

I believe this is an error because the second clause ("but could not hold it" is a dependent clause, so no comma must be used before "but". Am I right in this explanation? Could this be correct when used in British English?

2nd Sentence: He caressed her gloved hand, and just wished...

I also believe that this is an error because of the same explanation I have for the 1st sentence. the second clause ("and just wished..." is a dependent clause, which means that no comma must be used before "and". Am I also correct in this explanation? And Could this sentence be correct when the style used is found in British English?

Thank you to all that will help me!

I moved your post to the correct forum.

[Praxide Jebichii]

1st Sentence: Sara smiled at him, but could not hold it.
I believe this is an error .according to me, the comma should have been omitted and it will be correct
2nd Sentence: He caressed her gloved hand, and just wished...
In this case, the comma should also be omitted and the sentence "just wished''... completed to make the information clear.

[Helen Akoth]

I'm hoping some of y'all know whether these errors are grammatical or ungrammatical.

1st Sentence: Sara smiled at him, but could not hold it.

I believe this is an error because the second clause ("but could not hold it" is a dependent clause, so no comma must be used before "but". Am I right in this explanation? Could this be correct when used in British English?

2nd Sentence: He caressed her gloved hand, and just wished...

I also believe that this is an error because of the same explanation I have for the 1st sentence. the second clause ("and just wished..." is a dependent clause, which means that no comma must be used before "and". Am I also correct in this explanation? And Could this sentence be correct when the style used is found in British English?

Thank you to all that will help me!

The first sentence is definitely a punctuation error because, grammatically, one should not separate a dependent clause from an independent clause using a comma. The use of a comma in the second sentence is also an error due to the same reason, and both cases are not a matter of British or American English. Stylistically, some authors tend to violate such grammatical rules for various reasons, such as creating a certain literary effect. However, if you are writing an article where grammar is scrutinized, it is better to avoid such errors to be safe.