Common words:
* Bonjour: Hello
* Bien: Good, well
* Bon: Good
* Beau: Beautiful, handsome
* Belle: Beautiful (feminine)
* Blanc: White
* Bleu: Blue
* Boire: To drink
* Battre: To beat, to hit
* Bâtir: To build
Less common words:
* Balle: Ball
* Banane: Banana
* Barbe: Beard
* Bébée: Baby (feminine)
* Bœuf: Beef
* Bouton: Button
* Bruit: Noise
* Bureau: Desk
* Bus: Bus
* Baguette: Baguette (French bread)
More challenging words:
* Bénédiction: Blessing
* Bibliothèque: Library
* Brioche: Brioche (French bread)
* Brise: Breeze
* Brouillard: Fog
* Bâtiment: Building
* Boulevard: Boulevard
* Bénévole: Volunteer
* Biscuit: Biscuit
* Bouton d'or: Buttercup
This is just a small sample of French words starting with "B". There are many more!