Not all languages make the same distinction between W and V that English does. For this reason, the W and V sounds made by English speakers may no be clearly heard by non-native English speakers.

If this difficulty concerns yourself, consider this minimal pair exercise, and see an immense change in your spoken English muscle memory!

Follow along with these minimal pairs:
West v Vest  |  Went v Vent  |  While v Vile  |  Worst v Versed 

COACH WITH ME 1 ON 1