relative clause

Those who did find themselves struggling tended to all sit together at the back of the class, which were students we nicknamed 'The back-row innumerates'.

Which = those who

Milky, thanks
It is "which is" -- or you call into question the correctness of my grammar book?

MilkyThose who did find themselves struggling tended to all sit together at the back of the class, which were students we nicknamed 'The back-row innumerates'.

Which = those who --YEs, but then why "which is"

IMO,which is = the group of less clever students at the back of the class.

That 'which is students we gained the nickname of 'The back-row innumerates'.
....' sounds completely wrong to me as well. Not just the 'which is students part', but ' is students we gained' ....as well. As you have it, it is definitely incorrect.

Would you mind double-checking that you copied it 100% accurately from your grammar book? Did you perhaps miss out the words how and as?

So you had the answer already, did you? Why did you post this thread?

<"which were students we nicknamed 'The back-row innumerates'" No

Which is students we gained the nickname of 'The back-row innumerates'.>

Question: Were you one of those "back-row" students or were you part of the another group in the same class?

I'd go for the "which as students..." meaning.

I second Nona.

MilkySo you had the answer already, did you? Why did you post this thread?

Milky, I wonder when you will grow up.
By the way, how old are you?
It was a sentence whose structure I did not understand, and that is all.