were so long that they covered his hands

étaient si longues qu’elles lui couvraient les mains

→ be
phrase Rare #38,790
étaient si longues qu’elles lui couvraient les mains Structure « so + adjectif + that » : « si + adjectif + que ». « They » désigne ici les manches, et « covered his hands » signifie qu’elles recouvraient ses mains.
EN: The sleeves were so long that they covered his hands.
FR: Les manches étaient si longues qu’elles lui couvraient les mains.

The sleeves of his jumper were so long that they covered his hands.

Les manches de son pull étaient si longues qu’elles lui couvraient les mains.

His jumper's arms were so long that they covered his hands.

Les manches de son pull étaient si longues qu’elles lui couvraient les mains.

His jumper's sleeves were so long that they covered his hands.

Les manches de son pull étaient si longues qu’elles lui couvraient les mains.