In these sentences how do I know whether I should use who or whom?
This is the lady who/whom you said lives in the next house.
This is the lady who/whom you say everybody respects a lot
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
 This is the lady who/whom you said ____ lives in the next house.
 This is the lady who/whom you say everybody respects ____ a lot.
In  the pronoun is subject of the embedded "lives" clause, so it should be nominative "who".
In  the pronoun is object of "respects" so it should be accusative "whom". But nowadays people are less fussy about the distinction between "who and "whom" when the pronoun functions as object of a verb and regularly use nominative "who". In other words, both are correct in , but not .