Wełna jest ciepła.

to be

Breakdown of Wełna jest ciepła.

• ciepły: warm
• wełna: wool

Questions & Answers about Wełna jest ciepła.

Why is it ciepła and not ciepły?

Because wełna is a feminine singular noun, and adjectives in Polish must agree with the noun in gender, number, and usually case.

• ciepły = masculine singular
• ciepła = feminine singular
• ciepłe = neuter singular

Since wełna is feminine, the adjective must also be feminine: ciepła.

What part of speech is jest?

Jest is the 3rd person singular present tense form of the verb być, meaning to be.

So:

• ja jestem = I am
• ty jesteś = you are
• on/ona/ono jest = he/she/it is

In Wełna jest ciepła, jest means is.

Can I leave out jest and just say Wełna ciepła?

Normally, no. In standard Polish, if you are making a normal present-tense statement like Wool is warm, you usually keep jest.

So the natural sentence is:

• Wełna jest ciepła.

Polish sometimes omits forms of to be in special contexts, but not in a basic sentence like this one.