What is the difference between a tuna can and a can of tuna?

My answer:

A can of tuna is a can that has tuna in it. A tuna can is an empty can. It has nothing in it.

Is that right?

Omar AhmedIs that right?

Oh, yes. It's a basic principle of English for containers.

a tea cup / a cup of tea
a wine glass / a glass of wine
a beer mug / a mug of beer
a salad bowl / a bowl of salad
a water glass / a glass of water