Learn Hardcore Greek: Το πρωί ο καφές είναι καλός και το βράδυ είμαι στο σπίτι. - In the morning the coffee is good, and in the evening I am at home.

Greek often uses the definite article for generic statements. Ο καφές can mean “coffee (as a category).” Saying just καφές without an article here would sound odd, and ένας καφές would mean “a (single) coffee.”

Why is the adjective καλός (masculine) used instead of καλό or καλή?

Adjectives agree with the noun’s gender, number, and case. Καφές is masculine singular nominative, so the adjective must be masculine singular nominative: καλός. Feminine would be καλή, neuter καλό.

Why is it είναι in the first clause but είμαι in the second?

They are different persons of the verb “to be” (είμαι):

είναι = he/she/it is (3rd singular), matching the subject ο καφές.
είμαι = I am (1st singular), matching the understood subject “I.”

Do I need to say εγώ in (εγώ) είμαι στο σπίτι?

No. Greek is pro-drop: subject pronouns are usually omitted unless you want emphasis or contrast. Εγώ είμαι στο σπίτι would mean “I am at home (as opposed to someone else).”

What exactly is στο?

Στο is a contraction of the preposition σε (“in/at/to”) + the neuter article το (“the”): σε + το → στο. Other common contractions:

στον (σε + τον), masculine singular
στη(ν) (σε + τη(ν)), feminine singular
στους (σε + τους), masculine plural
στις (σε + τις), feminine plural
στα (σε + τα), neuter plural

Why is it στο σπίτι and not στον σπίτι?

Because σπίτι is neuter. The correct contraction is στο (neuter), not στον (masculine).

Can I say just σπίτι without the article, as in είμαι σπίτι?

Yes. Είμαι σπίτι means “I am home/at home” (more like an adverb). Είμαι στο σπίτι is “I am at the house/home,” a bit more concrete or location-focused. Both are common.

Why do we use το before πρωί and βράδυ? Aren’t we saying “in the morning/evening”?

Exactly. Greek often uses the neuter article + a time-of-day noun as an adverbial: το πρωί (in the morning), το βράδυ (in the evening), το μεσημέρι (at noon), το απόγευμα (in the afternoon). No extra preposition is needed.

Does το βράδυ mean “this evening/tonight” or “in the evenings (generally)”?

Both are possible; context decides. For specificity: σήμερα το βράδυ (“this evening”), or απόψε (“tonight”). For habitual meaning: τα βράδια (“in the evenings,” generally) or κάθε βράδυ (“every evening”).

Can I change the word order, e.g., put the time at the end?

Yes. Common alternatives:

Ο καφές είναι καλός το πρωί.
Το βράδυ είμαι στο σπίτι. / Είμαι στο σπίτι το βράδυ. Fronting time expressions (Το πρωί…, Το βράδυ…) is natural and slightly emphasizes the time.

Do I have to keep the verb είναι, or can I say ο καφές καλός?

You need the verb. Standard Greek uses the copula είμαι in such sentences: Ο καφές είναι καλός. Dropping it is not standard outside very telegraphic or headline-like styles.

How do I pronounce είμαι and είναι?

είμαι = í-me (EE-meh)
είναι = í-ne (EE-neh) In Modern Greek, ει is pronounced [i], and αι is pronounced [e].

Why is it ο καφές here but τον καφέ in other sentences?

Case. As the subject, it’s nominative: ο καφές. As a direct object (or after some prepositions), it becomes accusative: τον καφέ. For example: Πίνω τον καφέ. (“I drink the coffee.”)

How would I make the sentence negative?

Use δεν before the verb:

Το πρωί ο καφές δεν είναι καλός και το βράδυ δεν είμαι στο σπίτι. Note: δεν becomes δ’ only before vowels with smooth breathing in very formal writing; in modern usage you just write δεν.

What’s the difference between βράδυ and νύχτα?

βράδυ: evening/nighttime from sunset until late evening.
νύχτα: the night proper (late night). You can say τη νύχτα = “at night (late).”

Could I say “A coffee in the morning is good”?

Yes: Ένας καφές το πρωί είναι καλός. That means one cup/a coffee (not coffee in general). The original with ο καφές is generic.