a little+adjective+ noun

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. many thanks for the reply to my a little old topic
  2. many thanks for the reply to my a little the old topic
  3. many thanks for the reply to my a little an old topic

which is correct and why?

thanks

2

They are all wrong. You can use only one of “my” and “a”, and you cannot use multiple articles in a single noun phrase, like in “a little the old topic”.

You can say “Many thanks for the reply to my little old topic”. However, “little old” has a casual “folksy” feel that you may not have intended.