Learn Hardcore Croatian: U menzi na fakultetu danas imamo rižu, tjesteninu i salatu. - In the cafeteria at the university today we have rice, pasta, and salad.

The basic (dictionary) form is menza (cafeteria).
After the preposition u meaning in/at (no movement), Croatian uses the locative case.
The locative singular of menza is menzi.

So:

u menzi = in/at the cafeteria (location, static)
u menzu = into the cafeteria (movement toward, accusative case)
menza (no preposition) is just the nominative, the basic form.

Compare:

Radimo u menzi. – We work in the cafeteria. (locative: menzi)
Idemo u menzu. – We are going into the cafeteria. (accusative: menzu)

What is the difference between u menzi and u menzu?

The difference is static location vs. movement:

u menzi – locative case → you are already there
- Danas jedemo u menzi. – Today we eat in the cafeteria.
u menzu – accusative case → you are going there
- Idemo u menzu. – We are going into the cafeteria.

In your sentence, we are describing where the food is available (a static place), not movement, so u menzi is correct.

Why is it na fakultetu instead of u fakultetu?

Both na fakultetu and u fakultetu are grammatically possible, but they are used differently:

na fakultetu – the usual phrase meaning at the faculty / at university, focusing on the institution (studying, working there).
- Radim na fakultetu. – I work at the faculty.
- Učim na fakultetu. – I study at the faculty.
u fakultetu – very rare; would mean inside the faculty building, focusing on the physical interior (like saying inside the faculty building). Normally people would just say u zgradi fakulteta (in the faculty building) instead.

In the sentence U menzi na fakultetu danas imamo…, na fakultetu tells you which cafeteria: the one at the faculty / at the college, not just any random cafeteria.

Why do menzi and fakultetu have different endings, even though both mean “in/at” something?

They have different endings because they belong to different noun types (genders/declension patterns):

menza – feminine noun ending in -a
- Nominative: menza
- Locative: menzi → u menzi, o menzi
fakultet – masculine noun ending in a consonant
- Nominative: fakultet
- Locative: fakultetu → na fakultetu, o fakultetu

The prepositions decide which case you use (here: locative), and the noun type decides the ending:

feminine -a nouns → locative often -i (menza → menzi)
many masculine consonant nouns → locative -u (fakultet → fakultetu)

Can I change the word order, for example to Danas u menzi na fakultetu imamo rižu, tjesteninu i salatu? Does the meaning change?

You can change the word order; Croatian word order is flexible. All of these are correct:

U menzi na fakultetu danas imamo rižu, tjesteninu i salatu.
Danas u menzi na fakultetu imamo rižu, tjesteninu i salatu.
Danas imamo rižu, tjesteninu i salatu u menzi na fakultetu.

The basic meaning (what food, where, when) stays the same.

What changes is emphasis and what feels most natural:

Starting with Danas (Today) puts more focus on the day: what is happening today.
Starting with U menzi na fakultetu focuses on the location first: what’s available at that cafeteria.

All are acceptable in everyday speech. The original version sounds very natural as an announcement about the menu at that specific place.

Why is there no word for we in the sentence? Can I say Mi danas imamo…?

Croatian usually drops subject pronouns (like I, you, we) because the verb ending already shows the subject.

imamo is the 1st person plural form of imati (to have).
- (mi) imamo = we have

So:

Danas imamo rižu. – Today we have rice.
Mi danas imamo rižu. – Same meaning, but mi is explicitly stated.

You can say Mi danas imamo rižu, tjesteninu i salatu. It is grammatically correct, but in neutral statements it’s usually unnecessary, and can sound slightly more emphatic, like stressing we (as opposed to someone else) have it.

Why do riža, tjestenina and salata become rižu, tjesteninu i salatu?

They change because they are direct objects of the verb imamo, so they must be in the accusative case.

Base forms (nominative, dictionary form):

riža – rice
tjestenina – pasta
salata – salad

Accusative singular (what we have):

rižu
tjesteninu
salatu

Pattern: feminine nouns in -a usually change -a → -u in the accusative singular:

kava → kavu (coffee)
juha → juhu (soup)
salata → salatu (salad)

So imamo rižu, tjesteninu i salatu = we have rice, pasta and salad.

Are riža, tjestenina and salata singular or plural here? How do I talk about portions?

In this sentence they are singular, but they behave like mass nouns in English:

riža – rice (a mass substance)
tjestenina – pasta (mass)
salata – salad (can be mass or countable, depending on context)

Croatian often uses the singular for foods in a general/menu sense:

Danas imamo juhu i meso. – Today we have soup and meat.

To talk about portions, you usually add a measure word or a number:

jedna porcija riže – one portion of rice
dvije salate – two salads (two separate salads)
tri porcije tjestenine – three portions of pasta

So your sentence is like saying: On the menu today, we have rice, pasta and salad. — not counting individual plates.

Why is the verb imamo used here? Could I say jedemo or ima instead?

The verb imamo (we have) is standard for talking about what is on the menu / what is available:

Danas imamo rižu, tjesteninu i salatu.
= Today we have rice, pasta and salad (we are offering/serving them).

Alternatives:

jedemo – we eat / we are eating
- Danas jedemo rižu. – Today we are eating rice.
  This talks about what we are (going to) eat, not what the cafeteria offers to everyone.
ima – there is / there are (impersonal: literally it has)
- Danas u menzi ima riže, tjestenine i salate. – Today in the cafeteria there is rice, pasta and salad.
  This is also common; it sounds a bit more like an impersonal statement (“there is food X”), without focusing on we.

Your sentence with imamo fits well as something said by staff, or by students talking from their point of view about what’s on offer today.

Why is there a comma after rižu and tjesteninu, but no comma before i salatu?

This follows standard Croatian punctuation rules for lists:

Items are separated by commas:
rižu, tjesteninu
Before i (and) in a simple list, there is normally no comma:
rižu, tjesteninu i salatu

Croatian does not usually use the “Oxford comma” that English often uses before and:

English (with Oxford comma): rice, pasta, and salad
Croatian: rižu, tjesteninu i salatu (no comma before i)

You would add a comma before i only in more complex situations, for example when i connects two whole clauses, not just list items.

Can danas go somewhere else in the sentence, like at the beginning or at the end?

Yes, danas (today) is quite flexible in position. All of these are possible:

U menzi na fakultetu danas imamo rižu, tjesteninu i salatu.
Danas u menzi na fakultetu imamo rižu, tjesteninu i salatu.
U menzi na fakultetu imamo danas rižu, tjesteninu i salatu.
U menzi na fakultetu imamo rižu, tjesteninu i salatu danas. (possible, but the last position sounds a bit marked/emphatic)

Typical, most natural positions are:

at the very beginning: Danas u menzi na fakultetu imamo…
right before or after the verb: … danas imamo …

Placing danas at the very end can sound like you’re stressing today in contrast with other days, or it can just feel slightly less neutral.

Is menza a formal word? Are there other ways to say cafeteria in Croatian?

menza is informal/colloquial, but very common, especially for student cafeterias.

Other options:

kantina – canteen (also somewhat informal, but widely understood)
studentski restoran – student restaurant (more formal/official term in Croatia)
restoran – restaurant (more general)
restoran na fakultetu – the restaurant at the faculty
fakultetska menza / fakultetska kantina – the faculty cafeteria/canteen

In everyday student speech, menza is probably the most common word, so the sentence U menzi na fakultetu danas imamo… sounds very natural in that context.