Learn Hardcore Czech: V nemocnici dnes čeká také moje sestra, protože je tam naše babička. - In the hospital my sister is also waiting today, because our grandmother is there.

The basic form of the noun is nemocnice (a hospital), feminine.
After the preposition v meaning “in/inside” with a static location (no movement), Czech uses the locative case.

Nominative singular: nemocnice (dictionary form)
Locative singular: (v) nemocnici

So:

v nemocnici = in the hospital (location, locative)
do nemocnice = to the hospital (movement, accusative)

Nemocnice would be nominative, which does not work after v when you mean “in” a place.

Why is it čeká (3rd person singular) and not a plural form like čekají?

The subject of the main clause is only moje sestra (my sister), which is singular, so the verb must be singular: čeká.

The grandmother (naše babička) belongs to the second clause (protože je tam naše babička) and is not part of the subject of čeká. The sentence does not mean “my sister and our grandmother are waiting,” but “my sister is waiting, because our grandmother is there.”

Can I change the word order to Moje sestra dnes také čeká v nemocnici?

Yes, that is a completely natural word order. Czech word order is flexible, and all of these are possible with roughly the same meaning:

V nemocnici dnes čeká také moje sestra.
Moje sestra dnes také čeká v nemocnici.
Dnes v nemocnici také čeká moje sestra.

The differences are mostly about emphasis and what is “new” information. Starting with V nemocnici emphasizes the place; starting with Moje sestra emphasizes the person. Grammatically, all are fine.

What is the difference between také, taky, and i?

All can be translated as “also / too,” but they differ in style and nuance:

také – neutral, slightly more formal; good in both spoken and written Czech.
taky – very common in everyday speech, more informal/colloquial.
i – also means “also / even,” but is used differently in the sentence structure and can sound more emphatic.

In this sentence, you could say:

… dnes čeká také moje sestra … (neutral)
… dnes čeká taky moje sestra … (more colloquial)
… dnes čeká i moje sestra … (more like “even my sister is waiting” / “my sister too is waiting” – extra emphasis on my sister being included)

Why is it moje sestra and not můj sestra?

The possessive pronoun must agree in gender with the noun it modifies.

sestra (sister) is feminine.
For feminine nouns, the possessive “my” is moje (or má, see next question).
můj is masculine (for words like můj bratr – my brother).

So:

moje sestra = my sister
můj bratr = my brother

What is the difference between moje sestra and má sestra?

They mean the same thing: “my sister.”

moje sestra is the more common, neutral form in modern Czech.
má sestra is a short possessive form. It sounds a bit more formal, literary, or stylistically elevated, and in everyday speech it can sound old‑fashioned or “bookish.”

You will most often hear moje sestra in conversation. In writing (especially formal or literary), má sestra also appears.

Why is it naše babička (our grandmother) and not moje babička (my grandmother)?

Grammatically, both naše babička and moje babička are correct; the choice is about meaning and context.

naše babička = our grandmother (shared by the speaker and someone else, e.g., a sibling)
moje babička = my grandmother (focus on the speaker as the only reference point, or you simply choose not to mention others)

Czechs often use our (plural possessive) for close family members when they are shared within the family, so naše babička is very natural if the sister and the speaker share the same grandmother.

Why is it naše babička and not naši babičku?

The verb in the second clause is je (“is”), which is a linking verb. In Czech, the noun after je (or jsem, jsi, jsme, jste, jsou) is usually in the nominative case, because it is the subject complement, not an object.

Je tam naše babička. – babička in nominative (who is there? our grandmother).

You would use naši babičku (accusative) with verbs that take a direct object:

Vidíme naši babičku. – We see our grandmother. (direct object → accusative)

So je tam naše babička, not je tam naši babičku.

Why is there a comma before protože?

Protože introduces a subordinate clause (a “because”-clause). In Czech, you normally put a comma before most subordinating conjunctions, including:

protože (because)
když (when)
že (that)
aby (so that), etc.

So:

V nemocnici dnes čeká také moje sestra, protože je tam naše babička.

The comma separates the main clause (V nemocnici dnes čeká také moje sestra) from the subordinate clause of reason (protože je tam naše babička).

Can I put the protože‑clause first, like Protože je tam naše babička, v nemocnici dnes čeká také moje sestra?

Yes, that is perfectly correct:

Protože je tam naše babička, v nemocnici dnes čeká také moje sestra.

This order puts more emphasis on the reason first (“Because our grandmother is there…”). The grammar stays the same: the clause starting with protože still needs a comma separating it from the main clause.

Is tam necessary? What changes if I remove it?

You can grammatically say both:

… protože je tam naše babička.
… protože je naše babička.

However, tam (“there”) is very natural here, because it explicitly connects the reason with the place mentioned earlier (v nemocnici). Without tam, the sentence is still correct but sounds a bit less specific; adding tam makes the location clearer: our grandmother is there (in the hospital).

You can also change the word order:

Naše babička je tam.
Tam je naše babička.
Je tam naše babička.

All are possible; Je tam naše babička is a common, neutral order in this context.

What case and gender is nemocnici, and how is nemocnice declined?

Nemocnice is a feminine noun. In the sentence, nemocnici is:

gender: feminine
case: locative singular (after v = in, with no movement)

A simplified singular declension (one of the common patterns for nouns ending in ‑e):

Nominative: nemocnice (a hospital)
Genitive: nemocnice (of a hospital)
Dative: nemocnici (to/for a hospital)
Accusative: nemocnici (object, or motion to the hospital with do)
Locative: (o / v) nemocnici (about / in the hospital)
Instrumental: nemocnicí (with/by a hospital)

In our sentence it’s locative: v nemocnici = in the hospital.