Blaðran springur.

Because -n is the definite article attached to the noun.

• blaðra = a balloon
• blaðran = the balloon

In Icelandic, the is usually added to the end of the noun instead of being a separate word like in English.

Springur is the present tense of the verb springa.

In this sentence, it means bursts / pops.

So:

• Blaðran springur. = The balloon bursts / is bursting / pops.

Do not confuse this with the English verb spring. Even though they look related, in modern Icelandic springa often means to burst, explode, pop.

It is present tense, 3rd person singular.

That means it is used with subjects like:

• hann = he
• hún = she
• það = it
• or any singular noun, such as blaðran

So blaðran springur literally means the balloon bursts or the balloon is bursting depending on context.

Many Icelandic verbs in the present tense take -ur in the 3rd person singular.

For springa:

• infinitive: springa
• present, 3rd singular: springur

This is just part of the verb’s conjugation pattern, not something specific to this sentence alone.

Yes. Blaðran is the subject, and springur is the verb.

The sentence follows the basic pattern:

• Subject + Verb
• Blaðran springur.
• The balloon bursts.

Blaðra is a feminine noun.

That matters because noun gender affects:

• the form of the definite article
• adjectives
• pronouns
• some other grammatical endings

Here, the feminine singular nominative definite form is blaðran.

It is in the nominative case, because it is the subject of the sentence.

The basic dictionary form is blaðra.
In this sentence, the nominative singular definite form is blaðran.

A helpful approximation is:

• blaðran ≈ BLA-thran
• springur ≈ SPRIN-gur or SPRING-ur

A few useful pronunciation notes:

• ð in Icelandic is like the th in this in many contexts.
• r is usually a rolled or tapped r.
• The stress is normally on the first syllable: BLAÐ-ran, SPRIN-gur.

Exact pronunciation can vary a little, but those points will help a lot.

This sentence uses the most straightforward word order: subject + verb.

• Blaðran springur.

That is the normal, simple way to say it.

Icelandic can sometimes change word order for emphasis or because of sentence structure rules, but for a basic statement like this, this order is exactly what learners should expect.

Yes, depending on context.

The Icelandic present tense can sometimes overlap with several English choices:

• The balloon bursts
• The balloon is bursting
• The balloon pops

The exact English translation depends on the situation, but the Icelandic form itself is simply present tense.

It would be:

• Blaðra springur.

That means A balloon bursts or A balloon is bursting.

Compare:

• blaðra = a balloon
• blaðran = the balloon

So the only difference is the attached definite article -n.

It is not fully regular in the simple sense a beginner might expect, because the stem changes a bit between forms.

For example, you have:

• infinitive: springa
• present singular: springur

That vowel change is something learners will see in many Icelandic verbs. So it is worth learning verbs together with some key forms, not just the infinitive.