"Sora mea mi-a luat câinele, pe care nu - l plăceam deloc."
Traducere:My sister has taken my dog, which I did not like at all.
My sister HAS taken (present perfect) / My sister TOOK (past tense).
MY dog, NOT "me a dog"
pe care nu-l plăceam = which I DID NOT LIKE (past tense).
Even if it were "pe care nu îl plac", that's "which I don't LIKE", NOT which I dont liked.
Subject + do / does / don't / doesn't + verb in the infinitive, not the past tense.