La silla es de madera.

to be

Breakdown of La silla es de madera.

• la silla: the chair
• de: of
• la madera: the wood

Questions & Answers about La silla es de madera.

Why do we use es (from ser) instead of está (from estar) in this sentence?

In Spanish, ser describes inherent, permanent or defining characteristics—like what something is made of—while estar describes temporary states or locations. Because the material of the chair is an essential property, we say La silla es de madera, not está.

What is the function of de in de madera? Could I use con instead?

Here de indicates composition (“made of”).

• ser de + material = “to be made of [material]”
  You could use con (“with”) to describe something that has wood as part of it (e.g. una mesa con patas de madera = “a table with wooden legs”), but con does not express full composition the way de does.

Why don’t we put an article before madera? Why not de la madera?

When stating the material in a general sense, Spanish omits the article.

• una silla de madera = “a wooden chair”
  If you said de la madera, you’d be referring to a specific wood (“of the wood”) rather than material in general.

Can I say La silla es madera without ? Is that correct?