the conjunction 'or'

Hello everyone,
In my Collins Dictionary, they wrote:

A conjunction is a word that joins two parts of a sentence together. The words and, but and or are all conjunctions.
I like cricket and football, but i don’t like swimming or basketball.

As we see, we can use conjunction ‘or’ at the end of the sentence.
But in my American Heritage Dictionary 4th Edition, they wrote:

Usage Note-but: For one thing, if but were truly a conjunction here, we would expect the verb to agree in person and number with the noun or pronoun following but; we would then say No one but the students have read it. What is more, if but were a true conjunction here we would not expect that it could be moved to the end of a clause, as in No one has read it but the students.

According to the paragraph above, we cannot put conjunction at the end of a sentence or clause. So what is the truth about ‘conjunction’?

I don’t think the ‘or’ in the first sentence is at the ‘end’ of that sentence. ‘Basketball’ is the one at the end of that sentence.
In addition, if my understanding is correct, your quotation for American Heritage Dictionary is talking about ‘but’, not any other conjunctions.

First, neither word is at the end of the sentence there: “basketball” and “the students” come after. It doesn’t make sense to call that the end of the sentence.

Secondly, what makes this use of “or” and “but” special here is that they don’t have a full clause with them: only a few words come after the conjunction.

Here two full clauses are joined by “or”. A (full) clause is a phrase that contains a finite verb (like “will” here).

Here “or” joins two phrases that are not clauses (“Cleopatra” and “Marc Anthony”), as in your example. This is quite common, especially with coordinating conjunctions (conjunctions that join two parallel clauses or phrases, like “and”, “or”, and “but”).

But it can also occur with subordinating conjunctions:

Note that you can normally only use a phrase/fragment ( = not a full clause) if you can copy the missing information from the main clause: here it is only possible because the subject (“Cleopatra”) of the subordinate clause/fragment is the same as that of the main clause, and because the finite verb “was” can easily be added.

With coordinate conjunctions, it is less clear that you can copy the missing information to form two full clauses:

This is easy enough: I like cricket and [I like] football.

Here I can’t really expand the phrase after “or” into a full clause. That is because of “raising”, a special grammatical process that you can look up in Wikipedia. If I had to expand the sentence into full clauses, I would have to do it like this:

But this is a bit far fetched. It is easiest to remember that most coordinate conjunctions can easily be used with phrases that aren’t clauses.

That said, “but” is a bit special, because its meaning changes a bit when it is not used with a full clause but with a phrase/fragment as in your example; then it means something like “only”:

Here it means “only”, and this use of “but” is rather old fashioned.

With a negation (like “no”, “not”, “nothing”, “no-one”, etc.), “but” is still quite common in this way; it is not very old fashioned, though it is certainly not informal. It works like a preposition here: it means “except”. That is why your dictionary said it was not really a conjunction when used in this way, and I see; I just think that their “it is used at the end of the sentence” is not a very good clue.

So far I understand,

Too much jargon!

But here is ‘except’ that is just preposition not conjunction.

Please see at ‘Better English’ by Norman Lewis.

Everyone was happy but me.

Aren’t they link words?

Yes, they are conjunctions, i.e. words that join other words together.

Hi anhinh, by now your confusion got over? Or are you still in doubt? Any words or sentences that you use and are understood, then what’s the use of getting filthy advice just given by QU who thinks himself as a great thinker and seems to be thinking for the last 28 years.

PS: No hard feelings. I just wanted to make sure that the words I have used here are grammatically acceptable.

‘Sita, by now is your confusion got over? Or are you still in doubt?’
Is the above sentence correct?

You don’t need the double question mark, especially as you have used ‘or’ to link the questions.
Also, the first structure is incorrect.

Sita, are you over your confusion now or are you still in doubt?
Sita, have you got over your confusion now or are you still in doubt?

Beeesneees, Thank you so much for your continual help & support (correction over my sentences).