He put his helmet back on.

Source: Tatoeba

You need to wear a helmet.

Source: Tatoeba

Vikings didn't really wear horned helmets.

Source: Tatoeba

It is dangerous to ride a motorbike without a helmet.

Source: Tatoeba

You have to wear a helmet to protect your head.

Source: Tatoeba

I'd wear a helmet.

Source: Tatoeba