Regelbogen forklarer brætspillet.

Danish, like English, often makes compound nouns by joining words together.

Regelbogen breaks down as:

• regel = rule
• bog = book
• -en = the (common-gender singular definite ending)

So:

• regelbog = rulebook
• regelbogen = the rulebook

Writing it as one word is normal in Danish.

In Danish, the is often attached to the end of the noun instead of standing in front of it.

Here you have:

• Regelbogen = the rulebook
• brætspillet = the board game

This is called the definite form.

Compare:

• en regelbog = a rulebook

• regelbogen = the rulebook

• et brætspil = a board game
• brætspillet = the board game

So English uses a separate article, but Danish often uses an ending.

Because the two nouns have different grammatical genders.

• en regelbog → common gender
• et brætspil → neuter gender

In the singular definite form:

• common gender usually takes -en
• neuter usually takes -et

So:

• regelbog → regelbogen
• brætspil → brætspillet

This is very common in Danish and is something you usually have to learn along with each noun: en word or et word.

Forklarer is the present tense of forklare.

• at forklare = to explain
• forklarer = explain / explains / is explaining

Danish verbs do not change for person the way English does. So the same present-tense form is used with all subjects:

• jeg forklarer = I explain
• du forklarer = you explain
• han forklarer = he explains
• de forklarer = they explain

So in this sentence, Regelbogen forklarer brætspillet means the subject Regelbogen is doing the explaining.

This sentence uses the basic Danish main-clause order:

subject + verb + object

• Regelbogen = subject
• forklarer = verb
• brætspillet = object

So it matches normal English word order quite closely:

The rulebook explains the board game.

One important Danish rule is that in main clauses, the finite verb normally comes in second position. Here that happens naturally because the subject comes first.

Yes, often it can.

The Danish present tense can cover both:

• a general meaning: explains
• an ongoing meaning: is explaining

Which meaning is intended depends on context.

So Regelbogen forklarer brætspillet could mean:

• The rulebook explains the board game
• or, in some contexts, The rulebook is explaining the board game

Usually the broader context tells you which reading is natural.

No. Unlike German, Danish does not normally capitalize all nouns.

Regelbogen is capitalized here simply because it is the first word of the sentence.

If it appeared in the middle of a sentence, it would normally be written regelbogen.

So:

• Regelbogen forklarer brætspillet.
• Jeg læser regelbogen.

It is another compound noun:

• bræt = board
• spil = game
• -let / -et = the

So:

• brætspil = board game
• brætspillet = the board game

Again, Danish usually writes compounds as one word, just like regelbog.

It is grammatically clear and understandable, but depending on context, a Dane might more often say something a little more specific, such as:

• Regelbogen forklarer reglerne i brætspillet.
  = The rulebook explains the rules of the board game.

• Regelbogen forklarer, hvordan man spiller brætspillet.
  = The rulebook explains how to play the board game.

That said, Regelbogen forklarer brætspillet is useful for learning because it clearly shows:

• a definite subject noun
• a present-tense verb
• a definite object noun

A common difficulty is æ in brætspillet.

The letter æ is a front vowel that does not match a single English sound exactly. It is somewhat similar to the vowel in English cat, but not identical.

Other things to notice:

• Danish compounds are written as one word.
• The ending syllables in words like regelbogen and brætspillet are often less strongly pronounced than an English learner might expect.
• The r in Danish is not like a typical English r.

If you are practicing aloud, it helps to learn the words in chunks:

• regelbogen
• forklarer
• brætspillet

rather than trying to pronounce the whole sentence at once.