Be no slouch American British informal
To be extremely competent at something.
Jenny, a sporty girl, is no slouch on table tennis.
I adored Jenny so much since she was no slouch at implementing technology in daily life.
Linda is no slouch at acquiring a foreign language.
The verb "be" should be conjugated according to its tense.
Daughter: So I really want all my friends to have a great time. I was thinking it would be a good idea to have some candy out on the tables for people to snack on.
Mother: Well, if you want them to really enjoy themselves, candy is dandy but liquor is quicker.