Question: are all bronsted bases lewis bases?
Answer: Yes, all Bronsted-Lowry bases are Lewis base but all Lewis bases are not Bronsted-Lowry base. All Bronsted-Lowry bases must have a lone pair to accept a hydrogen, and all Lewis bases have lone pairs. While, Lewis bases may act as nucleophiles for any number of atoms: B, Al, C, etc; and not just for H.