Learn Hardcore Swedish: Hon lagar mat åt en kollega och en kund idag. - She cooks food for a colleague and a customer today.

tillaga = prepare/cook (a bit more formal or recipe-like: tillaga fisken)
koka = boil; baka = bake Avoid göra mat (“make food”)—that’s not idiomatic. Also, kock is a noun (“chef”); a verb like “to chef” isn’t standard (you might hear slangy kocka, but don’t rely on it).

Why is there no article with mat? Why not maten?

Mat is a mass noun and, in this generic sense, takes no article: laga mat = “cook (some) food.” Use the definite maten when referring to a specific meal/food already known: Hon lagar maten = “She is cooking the (specific) meal.”

Do I have to repeat en before both nouns (en kollega och en kund)?

Yes, if you mean two different people. En kollega och en kund clearly refers to two recipients. If you say en kollega och kund without repeating the article, it tends to suggest one person who is both colleague and customer.

Are kollega and kund both “en-words”? What are their forms?

Yes, both are common gender (en-words):

en kollega, kollegan, kollegor, kollegorna
en kund, kunden, kunder, kunderna

Can I use samt instead of och?

You can, but samt is more formal/literary (“as well as”). In everyday speech and writing, och is the default. To emphasize both elements, you can use både … och: Hon lagar mat åt både en kollega och en kund i dag.

Where can I place i dag/idag? What about word order and inversion?

Typical options:

Neutral: Hon lagar mat åt en kollega och en kund i dag.
With fronted time (V2 inversion): I dag lagar hon mat åt en kollega och en kund. You may also see mid-position: Hon lagar i dag mat åt …, which is acceptable but can feel a bit formal/bookish. Remember Swedish main clauses are V2: when you front an element (like i dag), the finite verb (lagar) stays in second position and the subject follows it.

Should I write idag or i dag?

Both are accepted. i dag is the traditional spacing; idag is very common in modern writing. Choose one style and be consistent, and prefer i dag in formal contexts if your teacher/style guide asks for it.

Can I say Hon är lagar mat to mean “She is cooking (right now)”?

No. Swedish doesn’t use “to be” + -ing. The simple present covers both habitual and ongoing actions: Hon lagar mat. If you really want to stress the ongoing nature, use Hon håller på att laga mat.

Where does inte go if I negate the sentence?

After the finite verb in a main clause:

Hon lagar inte mat i dag.
With fronting: I dag lagar hon inte mat. If you include the recipient phrase, it stays after the object: Hon lagar inte mat åt en kollega i dag.

Why use åt here? What’s the difference between åt, till, and för?

åt marks a beneficiary—doing something for someone’s benefit or on their behalf: Jag lagar mat åt min granne.
till focuses on the destination/intended recipient (often interchangeable with åt in this context): Jag lagar mat till min granne (I plan to serve/give it to them).
för is used for “for” in a broader sense (purpose, extent, in someone’s place): Jag lagade mat för 20 personer (for 20 people), Jag jobbade och lagade mat för henne (in her stead). With a single recipient, för is less idiomatic than åt/till with laga mat.

Isn’t åt also the past tense of “eat”?

Yes. åt is both a preposition (“for/to [someone’s benefit]”) and the past tense of äta (“to eat”). Context and word order distinguish them:

Verb: Hon åt i dag. (“She ate today.”)
Preposition: Hon lagar mat åt en kund i dag. (Here the finite verb is lagar, and åt introduces the recipient phrase.)

Should it be sin kollega instead of en kollega?

Use sin when you want to say “her own” (referring back to the subject): Hon lagar mat åt sin kollega … = “for her (own) colleague.”
If you use hennes, it refers to some other woman’s colleague: Hon lagar mat åt hennes kollega …
The original åt en kollega is indefinite and commonly understood as “for a colleague (of hers)” without insisting on the possessive.

Can I omit mat and say Hon lagar åt …?

Generally no—laga is transitive here and wants an object. Say Hon lagar mat åt … or name a dish: Hon lagar pasta åt … In casual speech, people might drop the obvious object if the context is crystal clear, but it’s safer to keep mat.

Is kund always right, or should it sometimes be gäst?

In restaurant/hospitality contexts, patrons are typically gäster (“guests”): Vi lagar mat åt våra gäster.
Kund is a customer in general business: Hon lagar mat åt en kund works if, say, she’s a private chef hired by a client.

Any quick pronunciation tips for this sentence?

Hon ≈ [huːn] (like “hoon”).
lagar ≈ [ˈlɑːɡar] (long “a” as in “father”; clear “g” and a tapped/trilled “r”).
mat ≈ [mɑːt] (long “a”).
åt ≈ [oːt] (long “o” like in “go,” but purer).
kollega ≈ ko-LEH-ga (stress on the middle syllable).
kund has the Swedish short “u” [ɵ], similar to French “u” in “lune.”
och is often pronounced just like o [o] in speech.
i dag/idag ≈ [iˈdɑːɡ] (the final “g” is audible).

Does och mean she’s cooking for both people?

Yes. … åt en kollega och en kund means both are recipients. If you meant one or the other, you’d use eller. To make “both” explicit, use både … och: … åt både en kollega och en kund.