Learn Hardcore Spanish (Latin America): Caliento agua en la tetera y sirvo té para todos. - I heat water in the kettle and serve tea for everyone.

In Spanish you often drop the article with uncountable/mass nouns when you mean an unspecified amount. Caliento agua = I heat some water. Use el agua only when you mean specific water: Caliento el agua de la tetera, Bebo el agua que sobró.

But isn’t it el agua even though agua is feminine?

Yes. Agua is feminine, but in the singular it takes el instead of la to avoid two a-sounds together. Agreement stays feminine: el agua fría, esta agua; in the plural it’s regular: las aguas frías.

If it’s el agua, is the pronoun la or lo?

Feminine: la. The article switches to el for sound, but the gender is still feminine. Example: El agua está fría. Ya la calenté. Not lo.

Should it be hiervo agua instead of caliento agua?

Use calentar when you heat something (not necessarily to boiling). Hervir means to boil. So:

Caliento agua = I heat water.
Hiervo agua / Pongo a hervir el agua = I boil the water. Choose based on meaning.

Are caliento and sirvo irregular forms?

Yes, both are stem-changing in the present.

Calentar (e → ie): yo caliento, tú calientas, él/ella calienta, nosotros calentamos, ustedes/ellos calientan.
Servir (e → i): yo sirvo, tú sirves, él/ella sirve, nosotros servimos, ustedes/ellos sirven.

Why en la tetera? Could I say en una tetera?

Both work. En la tetera = in the (known/specific) kettle/teapot. En una tetera = in a kettle/teapot (not specific). Pick definite vs. indefinite as in English.

Does tetera mean kettle or teapot in Latin America?

Often tetera is the teapot used to brew/serve tea. For a kettle (to heat water), common terms are:

hervidor (widely used for electric kettles: Chile, Peru, Mexico, etc.)
pava (Argentina, Uruguay, Paraguay; also for mate) So you might hear: Caliento agua en el hervidor y la sirvo con la tetera.

Why is there no article with té? When would I say un té?

As a mass noun, beverages often appear without an article for an indefinite amount: sirvo té, bebo café, tomo agua. Use un té for a single serving (a cup): ¿Quieres un té? Plural for servings/types is possible: dos tés.

Is para todos the best choice? What about a todos?

Both are fine, with a nuance:

Sirvo té a todos marks the recipients (indirect object) and is very natural.
Sirvo té para todos emphasizes “for everyone” (intended recipients/portioning). In many situations they’re interchangeable.

Should I add an indirect object pronoun? Like Les sirvo té a todos?

That’s very idiomatic. Spanish often “duplicates” the indirect object: Les sirvo té a todos. It’s optional here but common, especially when you highlight the recipients.

Is the a in a todos the personal a?

Here a introduces the indirect object (the recipients), not the “personal a” for direct objects. With servir, the drink is the direct object (té) and the people are the indirect object (a todos / les).

Does para todos include me, the speaker?

It can, depending on context. If you want to include yourself, say para todos nosotros. To exclude yourself and address others, para ustedes. To refer to another group, para todos ellos.

Why does té have an accent?

To distinguish the noun té (tea) from the pronoun te (you, object pronoun). The accent marks the different word and stress.

Do I ever change y to e here?

No. Y only changes to e before words that start with the i sound (i-/hi-): padres e hijos, iglesias e institutos. Since sirvo starts with s, keep y. Also, with words like hielo (pronounced with a y-sound), you keep y: agua y hielo.

Could I say Estoy calentando agua… instead of the simple present?

Yes. Spanish allows both. The simple present often covers actions in progress: Ahora caliento agua… is natural. Estoy calentando agua… explicitly highlights that it’s happening right now.

Why not todas instead of todos?

Use todos for a mixed or unspecified group, and todas only if the group is exclusively female. So para todas fits only for an all-female group.

Is there any risk that sirvo is read as “I am useful”?

Context avoids that because sirvo here takes a direct object (té) and/or recipients (para/a todos). The “be useful” sense appears with sirvo para…: for example, No sirvo para cocinar.

How would I say “I’ll serve it to everyone” using pronouns?

Use both an indirect and a direct object pronoun: Se lo sirvo a todos. Before lo/la/los/las, le/les becomes se: you say se lo, not les lo.