Jeg drikker mindre kaffe om aftenen.

Drikker is the present tense form of the verb at drikke (to drink).

• jeg drikker = I drink / I am drinking
• drik! = drink! (an imperative/command)

So in this sentence, drikker is correct because the speaker is making a normal statement, not giving an order.

Danish works like English here:

• mindre = less for uncountable things
• færre = fewer for countable things

Kaffe is usually treated as an uncountable noun, so:

• mindre kaffe = less coffee

Compare:

• mindre kaffe = less coffee
• færre kopper kaffe = fewer cups of coffee

Because kaffe is being used in a general, uncountable way.

In English, we also usually say:

• I drink less coffee in the evening not
• I drink less a coffee in the evening

So Danish does the same:

• mindre kaffe = less coffee

If you were talking about a specific coffee, the structure would be different, but here it just means coffee in general.

Mindre is a comparative form meaning less. The comparison is often implicit.

So Jeg drikker mindre kaffe om aftenen can mean:

• I drink less coffee in the evening
• I drink less coffee in the evening than before
• I drink less coffee in the evening than at other times of day
• I drink less coffee in the evening than I used to

If you want to state the comparison clearly, Danish can use end (than):

• Jeg drikker mindre kaffe om aftenen end om morgenen. = I drink less coffee in the evening than in the morning.

This is a very common Danish time expression.

Om aftenen means in the evening / in the evenings, usually in a general or habitual sense.

The noun appears in the definite form:

• aftenen = the evening

This happens in several fixed time expressions in Danish:

• om morgenen = in the morning
• om dagen = in the daytime / during the day
• om aftenen = in the evening
• om natten = at night

So even though English does not say in the evening with the same grammar idea, Danish normally does.

This is an important distinction:

• om aftenen = in the evening / in the evenings, generally or habitually
• i aften = this evening / tonight, one specific evening

So:

• Jeg drikker mindre kaffe om aftenen. = I drink less coffee in the evening / in the evenings.
  This sounds like a habit or general pattern.

• Jeg drikker mindre kaffe i aften. = I’m drinking less coffee tonight.
  This refers to tonight specifically.

The sentence has very normal Danish main-clause word order:

• Jeg = subject
• drikker = verb
• mindre kaffe = object phrase
• om aftenen = time expression

So the pattern is basically:

Subject + verb + object + time expression

That gives:

Jeg drikker mindre kaffe om aftenen.

This is one of the most basic and common word orders in Danish.

Normally, no. Mindre belongs with kaffe, because together they form the noun phrase mindre kaffe (less coffee).

So the natural structure is:

• Jeg drikker mindre kaffe om aftenen.

If you say:

• Jeg drikker kaffe mindre om aftenen

it sounds unnatural, because it separates mindre from the thing it modifies.

Think of mindre kaffe as one unit.

Yes. In many cases, the Danish present tense can correspond to both:

• I drink
• I am drinking

So Jeg drikker mindre kaffe om aftenen is usually understood as a general habit:

• I drink less coffee in the evening

If context made it relevant, jeg drikker could also describe something happening now, but in this sentence the time phrase om aftenen makes it sound habitual.

A rough learner-friendly guide might be:

• Jeg ≈ yai
• drikker ≈ DRIG-er
• mindre ≈ MIN-dra
• kaffe ≈ KAH-fe
• om ≈ om
• aftenen ≈ AF-te-nen

A few useful notes:

• jeg is often pronounced much more like yai than the spelling suggests.
• drikker has a soft, quick ending.
• mindre often has a weak final vowel.
• aftenen is usually spoken smoothly, not with heavy stress on every syllable.

Actual Danish pronunciation varies by speaker and region, and spoken Danish is often softer and more reduced than learners expect.

Yes. Danish often uses the same expression for both a general time period and a repeated habit.

So om aftenen can mean:

• in the evening
• in the evenings

The exact English translation depends on context. In this sentence, because it describes a general habit, in the evenings is often a very natural translation.

Because Danish does not use do-support the way English does.

English sometimes needs do / does / did in statements, questions, or negatives:

• Do you drink coffee?
• I do not drink coffee.

Danish usually does this more directly with the main verb itself:

• Drikker du kaffe? = Do you drink coffee?
• Jeg drikker ikke kaffe. = I do not drink coffee.

So in Jeg drikker mindre kaffe om aftenen, Danish simply uses the main verb drikker with no extra helping verb like do.