Breakdown of У меня дрожали губы, когда я пил холодную воду на морозе.
Questions & Answers about У меня дрожали губы, когда я пил холодную воду на морозе.
Both are possible, but У меня дрожали губы is a very common and natural Russian way to talk about body parts and physical states.
Literally, it is something like At me, lips were trembling, but in natural English it means My lips were trembling.
Russian often avoids possessive words like мой / моя / мои when it is already obvious whose body part is being discussed. So with body parts, feelings, and physical conditions, у + genitive is extremely common.
- У меня дрожали губы = My lips were trembling
- У него болела голова = His head hurt
- У неё замёрзли руки = Her hands got cold
Мои губы дрожали is grammatically correct, but it sounds more marked or emphatic in many contexts.
Because the subject is губы, which is plural.
In the past tense, Russian verbs agree with the subject in number, and in the singular they also agree in gender.
- губа дрожала = the lip was trembling
- губы дрожали = the lips were trembling
So дрожали is the past plural form of дрожать.