"Ja mam spodnie."

Translation: I have trousers.

[DenisFell]

Pants is an American word for trousers.
Interestingly, when we ( english speakers ) talk about trousers we refer to a pair of trousers, or a pair of shoes ,a pair of pants or socks.
Its just normal for us and yet a pair is normally 2. Shoes and socks come as a pair when you purchase them.

[Jellei]

In Polish it's also plural "spodnie" but "para spodni" (a pair of them) is still about just one item. And then "para skarpetek" (a pair of socks) is two socks. Basically exactly the same.