Vi køber foder til kaninen, og senere køber hun også foder til hamsteren.

Because in Danish, the definite article is usually attached to the end of the noun instead of standing as a separate word.

• kanin = rabbit
• kaninen = the rabbit
• hamster = hamster
• hamsteren = the hamster

So til kaninen means for the rabbit, and til hamsteren means for the hamster.

Foder is specifically feed / animal food, so it is the natural word when talking about food for pets or animals.

• foder = feed, pet food, animal food
• mad = food in a more general sense, often human food

So køber foder til kaninen sounds much more natural than using mad here.

Here, til means for.

So:

• foder til kaninen = feed for the rabbit
• foder til hamsteren = feed for the hamster

Danish til often covers meanings like to, for, or until, depending on context. In this sentence, for is the right meaning.

Because the subject changes.

• Vi = we
• hun = she

So the first clause says we buy feed for the rabbit, and the second clause says later she also buys feed for the hamster.

Grammatically, this is completely normal: one clause can have one subject, and the next clause can have a different one.

This is because Danish main clauses usually follow the verb-second rule, often called V2.

When senere is placed first for emphasis or as a time expression, the finite verb must come immediately after it:

• Senere køber hun også foder til hamsteren.

Structure:

• Senere = first element
• køber = finite verb in second position
• hun = subject
• også = also

If you started with hun, you could say:

• Hun køber også foder til hamsteren senere.

That is also possible in many contexts, but it is not the same word order as the sentence you were given. The original sentence emphasizes later by putting senere first.

Også means also / too.

In this sentence:

• senere køber hun også foder til hamsteren

it means that she also buys feed for the hamster, in addition to something else already mentioned.

Its position is typical in Danish. It often comes after the subject in a main clause, especially after the finite verb if another element has been placed first.

So the placement here is natural Danish word order.

Yes. Køber is the present tense of købe (to buy).

• at købe = to buy
• jeg køber = I buy / I am buying
• vi køber = we buy / we are buying
• hun køber = she buys / she is buying

As in English, the simple present can sometimes translate naturally as either buy or are buying, depending on context.

Because Danish often repeats the noun when that makes the sentence clear and natural.

So:

• Vi køber foder til kaninen, og senere køber hun også foder til hamsteren.

is straightforward and clear.

You can sometimes leave out repeated words in Danish if the meaning is obvious, but repeating foder here sounds natural and avoids any ambiguity.

Og means and. It joins the two clauses:

• Vi køber foder til kaninen
• og senere køber hun også foder til hamsteren

So it connects two related actions into one sentence.

Usually, Danish puts the definite article at the end of the noun:

• kaninen = the rabbit
• hamsteren = the hamster

This is one of the big differences from English.

However, Danish can also use a separate definite word such as den or det, but that usually happens when there is an adjective:

• kaninen = the rabbit
• den store kanin = the big rabbit

So in your sentence, because there is no adjective, the ending -en is enough.

The base forms are:

• kanin = rabbit
• hamster = hamster

Then Danish adds the definite ending:

• kanin → kaninen
• hamster → hamsteren

Both of these nouns are common gender nouns, which is why the definite singular ending is -en.

The letter ø is a vowel that English does not really have in the same way. It is pronounced with rounded lips, somewhat like the vowel in French deux or German schön, if you know those.

So:

• køber is roughly like KUR-ber or KER-ber with rounded lips, but not exactly either English sound.

A few helpful points:

• ø is its own letter in Danish
• it is not pronounced like English o
• the -er ending in Danish is usually a light, reduced sound

The important thing for a learner is to notice that køber and kober would not sound the same.

Literally, til can often mean to, but in this sentence the natural English translation is for:

• foder til kaninen = feed for the rabbit
• not usually feed to the rabbit

So while til is often a broad preposition in Danish, you should translate it according to the whole phrase, not word by word.