Jeg drikker som regel te om aftenen, hvis jeg skal op tidligt.

Because drikker is the present tense of at drikke (to drink).

• at drikke = to drink
• jeg drikker = I drink / I am drinking

In Danish, the present tense usually ends in -r:

• jeg bor = I live
• jeg spiser = I eat
• jeg drikker = I drink

So jeg drik is not a correct finite verb form here.

Som regel means usually / as a rule.

In this sentence, it comes after the verb:

• Jeg drikker som regel te ...

That placement is very natural in Danish for an adverbial expression of frequency. Danish often puts these kinds of adverbs after the finite verb in main clauses.

Compare:

• Jeg drikker som regel te. = I usually drink tea.
• Jeg går som regel tidligt i seng. = I usually go to bed early.

Because te is being used as an uncountable noun here, just like tea in English.

So:

• Jeg drikker te = I drink tea

You would only use an article if you meant a specific tea or a serving in a context that requires it:

• en te can sometimes mean a tea in certain contexts, but it is much less neutral than simply te
• teen = the tea

In this sentence, plain te is the normal choice.

Om aftenen means in the evening.

This is a very common Danish pattern:

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

The -en ending on aftenen is the definite form (the evening), but in this fixed expression the whole phrase simply means in the evening.

Because om aftenen is the normal way to talk about something happening in the evenings / in the evening generally.

There is an important difference:

• om aftenen = in the evening, as a general time of day
• i aften = tonight

So in your sentence:

• Jeg drikker som regel te om aftenen = I usually drink tea in the evening

If you said i aften, it would mean tonight, which is more specific:

• Jeg drikker te i aften = I’m drinking tea tonight

Hvis means if.

It introduces a condition:

• hvis jeg skal op tidligt = if I have to get up early

So the whole second part explains under what condition the speaker usually drinks tea in the evening.

Very common examples:

• Hvis det regner, bliver jeg hjemme. = If it rains, I stay home.
• Hvis jeg har tid, kommer jeg. = If I have time, I’ll come.

Skal op is a very common Danish expression meaning have to get up.

• skal = must / have to / am supposed to
• op = up

So:

• jeg skal op tidligt = I have to get up early

Danish often uses short particles like op, ud, ind, hjem, etc. with verbs to create meanings that English often expresses with a phrasal verb:

• stå op = get up
• gå ud = go out
• komme ind = come in

Here, even though stå is not written, skal op is idiomatic and very common.

Because Danish uses the present tense for habits and routines, just like English often does.

• Jeg drikker som regel te ... = I usually drink tea ...

This is not about one specific moment right now. It describes something that happens regularly.

Danish present tense can cover:

• habits: Jeg løber hver dag. = I run every day.
• general truths: Vand koger ved 100 grader. = Water boils at 100 degrees.
• current actions in some contexts: Jeg læser. = I’m reading / I read.

Because in a subordinate clause introduced by hvis, Danish normally keeps the order:

subject + finite verb + other elements

So:

• hvis jeg skal op tidligt

Breaking it down:

• hvis = if
• jeg = subject
• skal = finite verb
• op = particle
• tidligt = adverb

This is different from main clauses, where Danish often uses verb-second word order.

Compare:

Main clause:

• Jeg drikker som regel te.

Subordinate clause:

• ..., hvis jeg skal op tidligt.

Yes. That would be perfectly natural.

You can say:

• Hvis jeg skal op tidligt, drikker jeg som regel te om aftenen.

When a subordinate clause comes first in Danish, the main clause still follows the verb-second rule, so you get:

• ..., drikker jeg ... not
• ..., jeg drikker ...

That word order is very important.

Because Danish normally uses a comma before a subordinate clause, and hvis introduces one.

So:

• Jeg drikker som regel te om aftenen, hvis jeg skal op tidligt.

This comma is standard in Danish writing and helps show that the second part is dependent on the first.

No, but it is one of the most common and natural choices.

Other possibilities include:

• normalt = normally
• ofte = often

But they are not exactly the same:

• som regel = usually / as a rule
• normalt = normally
• ofte = often

So:

• Jeg drikker som regel te ... = I usually drink tea ... sounds very natural for a general habit.

A careful pronunciation would be something like:

Yai DRIK-er som REI-el tay om AF-ten-en, vis yai skal op TID-lee

A few helpful notes:

• jeg often sounds more like yai
• drikker has a short i
• regel is often pronounced more like rei-el
• te is usually like tay
• tidligt often sounds closer to TID-lee in connected speech

As usual, real spoken Danish is more reduced than the spelling suggests, so listening to native audio is especially useful.