On the use of prepositions

I hope very much that the following sentence is incorrect:
"I read newspapers on mornings except on sunday mornings".

Am I right that the second entry of 'on' is a mistake?

To me, it is much more natural to say "I read newspapers in the morning, except on Sunday mornings."

The second "on" sounds perfectly ok.

Ant_222 :

Your intuition is correct that
I read the newspaper every morning, except Sunday mornings.
is perfectly correct. The sentence with 'on Sunday morning' is fine too.

Some sentences that would not be correct are:
* I read the newspaper every morning, except a Sunday morning.
* I read the newspaper every morning, except the Sunday morning.

Re: "I read newspapers on mornings except on sunday mornings".

There are numerous ways you can say this . While the sentence you proposed can be understood by any English speaker, it sounds a little wordy. Ved and D mention some good points.

Other ways that sound more thrifty and /or more natural are:
1) I read newspapers every morning except on Sunday.
2) Even "I read the paper every mornin' 'cept Sundays" if you don't mind sounding country.

Thank you very much. Thus, my English teacher is wrong. She is sure that the second 'on' is necessary.

I agree with your English teacher.
"except Sundays" is merely the lazier version of
"except on Sundays"
and I'm not sure if it's accepted as grammatically correct in Standard Englsih yet. It probably is for speech but not writing.

It is the first "on" in the sentence which is incorrect, as Ved pointed out.

What do people think, is it grammatically correct when you modify the word 'mornings' with another word:
"I read newspapers on mornings off, except on sunday mornings"
"I read newspapers on weekday mornings, except on sunday mornings"
?
I know the meaning is nonsensical here, and the grammar's not great, but I don't think it's incorrect..

I think "mornings off" is idiomatic, like "day off," and is correct.

I read newspapers every morning except on Sundays seems to be ok