Bad milk tastes sour.

Vinegar has a sharp taste.

I told you again and again.

Milk easily turns sour.

The milk turned sour.

The milk has turned sour.

If you add lemon, it will become sour.

Lemons and limes are acidic fruits.

Lemon is sour.

The lemon is a sour fruit.

Lemons are sour.

The milk went sour.

Acid fruits like pineapples and lemons are sour.

Is it sweet or sour?

The milk tastes sour.

The fruit is still too sour to eat.

The milk tasted sour.

The grapes seem to be sour.

Those grapes look sweet, but in fact they're sour.

The orange didn't taste either sweet or sour.