Please correct my statements

1) I was absent at/on last class.
2) Please, join (to) our group.
3) your answer seems to me excellent.

No.
1) I was absent from the last class.
2) Please, join our group.
3) Your answer seems to me excellent.

Thank you Clive.
But I have not understood that "I was absent from the last class". Why "from", why not 'at'?

mizansinha007....But I have not don't understand that "I was absent from the last class". Why "from", why not 'at'? Because you were not at the last class.
'I was not at the last class.' is also correct.

3) your answer seems to me excellent. I wouldn't say that.

Y

mizansinha007Thank you Clive.But I have not understood that "I was absent from the last class". Why "from", why not 'at'?

Because it should be absent from, not absent at.

No.
1) I was absent at last class.
2) Please, join to our group.
3) your answer seems to me excellent.

They are incorrect, as has been pointed out.

Please do not post responses unless you have checked them in a reliable grammar.

fivejedjonPlease do not post responses unless you have checked them in a reliable grammar.

Or at least checked the rest of the thread you are posting in, so you do not repeat suggestions that have already been judged incorrect.