Baseball er populært.

When Norwegian talks about a sport in general, it usually uses the noun by itself, without en, ei, or et. So Baseball here means the sport as a general activity, not a specific item.

Compare:

• Baseball er populært. = talking about the sport in general
• Dette er en baseball. = talking about a baseball, the ball itself

Er is the present tense of å være = to be.

Unlike English, Norwegian does not change this verb for different subjects in the present tense:

• jeg er
• du er
• han er
• vi er

So er is used for all persons and numbers in the present.

This is one of the most useful things to notice in the sentence.

The adjective populær changes form depending on grammar. Here it appears as populært, the neuter singular form.

With sports, activities, and general ideas, Norwegian often uses the neuter form of the adjective when describing the activity as a whole:

• Baseball er populært.
• Fotball er morsomt.
• Å lese er interessant.

You can think of it as meaning something like Baseball, as an activity, is popular.

If you add a noun like sport, the adjective agrees with that noun instead:

• Baseball er en populær sport.

Here sport is a common-gender noun, so the adjective is populær, not populært.

Usually, no. Common nouns are normally lowercase in Norwegian, just like most common nouns in English.

It is capitalized here only because it is the first word of the sentence.

So in the middle of a sentence, you would normally write:

• Jeg synes baseball er populært.

Yes, absolutely. That is also a very natural sentence.

There is a small difference in structure:

• Baseball er populært. = describes baseball in a general way
• Baseball er en populær sport. = explicitly says it is a popular sport

Both are correct. The second version is a little more specific because it includes the noun sport.

The word order is the basic Norwegian statement pattern:

subject + verb + adjective

So here:

• Baseball = subject
• er = verb
• populært = adjective

This is the normal order for a simple declarative sentence in Norwegian.

A simple approximation is:

po-po-LÆRT

A few helpful points:

• the stress is on the last syllable: -lært
• æ sounds somewhat like the vowel in cat, though not exactly the same
• in many dialects, rt is pronounced as a single retroflex sound rather than a clear r plus t

You do not need perfect pronunciation right away, but it helps to notice that the last syllable is the strongest one.

Yes, very often.

You can make similar sentences such as:

• Tennis er populært.
• Fotball er populært.
• Basketball er populært.

This pattern is very common for talking about sports and activities in a general sense.