Learn Hardcore Polish: On umie nalewać herbatę do kubka. - He knows how to pour tea into a mug.

umie = knows how (learned skill). Natural and neutral here.
potrafi = is capable (often stresses achieving a result or being able to do it in a given situation; a bit more emphatic/formal). Also fine: On potrafi nalać herbaty do kubka.
może = may/can because it’s allowed or possible, not about skill: On może nalewać herbatę (He’s allowed to pour tea).

Why is it herbatę and not herbata?

herbatę is the accusative singular (feminine) of herbata, used for the direct object of nalewać.
With perfective nalać, Polish often uses the partitive genitive to mean “some”: nalać herbaty (do kubka).
With imperfective nalewać, both are possible; nalewać herbatę (neutral) vs nalewać herbaty (emphasizes “some amount of tea”).

Why do kubka and not w kubek?

do + genitive marks movement toward a destination; it’s the default with pouring: nalewać do kubka.
w + accusative also means “into,” but it collocates more naturally with verbs like wlewać/wlać. You’ll hear wlać do/w kubka, but with nalewać the safest choice is do.
Static “in the mug” is w kubku (locative).

What’s the difference between nalewać and nalać here?

nalewać (imperfective) focuses on the ongoing action/skill. With ability, it signals general know‑how: On umie nalewać…
nalać (perfective) focuses on a single, completed result: On umie nalać herbaty do kubka = he can successfully pour (get it done).

Do I need the pronoun On?

No. Polish drops subject pronouns when context is clear. Umie nalewać herbatę do kubka is the usual, neutral version. Keeping On adds contrast/emphasis (e.g., “He can (but others can’t)”).

Can I change the word order?

Yes, for emphasis. Some natural options:

Neutral: Umie nalewać herbatę do kubka.
Emphasize the object/destination: Herbatę do kubka umie nalewać.
Emphasize destination: Do kubka umie nalewać herbatę. Polish is flexible, but the original order is the most neutral.

How do I pronounce it?

Stress is always on the second‑to‑last syllable: u‑MIE na‑LE‑wać her‑BA‑tę do KUB‑ka.
Tips:
- w sounds like English “v.”
- ć (in nalewać) is a soft “tch” sound.
- h/ch (in herbatę) is like the “ch” in Scottish “loch.”
- ę (in herbatę) is a nasal “e,” but before t many speakers just say plain “e.”

Is nalewać only for liquids? What about other substances?

nalewać is for liquids.
For pouring solids (sugar, rice), use wsypywać/wsypać.
Related verbs:
- lać = to pour (general; also “it’s raining”: Leje).
- wlewać/wlać = to pour into (focus on the destination).
- dolewać/dolać = to pour in more/top up.
- rozlewać/rozlać = to spill or distribute into many vessels.

Can I omit do kubka?

Yes. On umie nalewać herbatę is fine if the destination is obvious or unimportant. Leaving out the object entirely (On umie nalewać) usually sounds incomplete unless context makes it clear or it’s said jokingly.

What’s the difference between kubek, filiżanka, and szklanka?

kubek = mug (with a handle). Genitive: kubka → do kubka.
filiżanka = teacup/coffee cup. Genitive: filiżanki → do filiżanki.
szklanka = drinking glass/tumbler. Genitive: szklanki → do szklanki.

How does umieć work with an infinitive, and how do you conjugate it?

Pattern: umieć + infinitive (no extra “to”). Hence umie nalewać, not “umie w nalewaniu.”
Present conjugation:
- ja umiem, ty umiesz, on/ona/ono umie
- my umiemy, wy umiecie, oni/one umieją
In the present tense it doesn’t change for gender: on umie / ona umie.

How would I give a command like “Pour the tea into the mug”?

Singular informal: Nalej herbaty do kubka.
Plural/informal group: Nalejcie herbaty do kubka.
Polite/formal: Niech pan/pani naleje herbaty do kubka. Using perfective (nalać) plus genitive (herbaty) sounds natural for “some tea” as a completed action.