Learn Hardcore Norwegian: Jeg møter henne tilfeldig i byen.

a present event: I (am) meet(ing) her by chance in town.
a habitual action: I (often) meet her by chance in town.
even a near-future meaning in the right context: Tomorrow I meet her… (though then it wouldn’t really be tilfeldig / by chance).

Norwegian present tense is used quite broadly, similar to English I meet / I am meeting depending on context.

Why is it henne and not hun?

Norwegian, like English, has different pronouns for subject and object:

hun = she (subject form)
henne = her (object form)

In the sentence:

Jeg (I) is the subject: the one doing the meeting.
henne (her) is the direct object: the one being met.

So you say:

Hun møter meg. – She meets me.
Jeg møter henne. – I meet her.

Using hun here (Jeg møter hun) would be grammatically wrong, just like I meet she is wrong in English.

What exactly does tilfeldig mean here? Is it like “by accident,” “randomly,” or “coincidentally”?

In this context, tilfeldig means by chance / coincidentally.

Nuance:

Jeg møter henne tilfeldig i byen.
→ I happen to run into her / I meet her by chance in town.

It does not usually mean “I did something wrong by mistake” (like pressing the wrong button). For that, Norwegian more often uses:

ved et uhell – by accident / unintentionally
e.g. Jeg sendte meldingen ved et uhell. – I sent the message by accident.

So:

tilfeldig = coincidentally, not planned.
ved et uhell = by accident, as in a mistake.

You can strengthen it with helt:

Jeg møter henne helt tilfeldig i byen. – I meet her completely by chance in town.

Can tilfeldig go in other positions in the sentence, or must it stay where it is?

Adverbs in Norwegian are fairly flexible, but there are preferred positions. The neutral, most natural place here is after the verb and object:

Jeg møter henne tilfeldig i byen. ✅ (standard, natural)

Other possibilities and their feel:

Jeg møter henne i byen tilfeldig.
Sounds a bit awkward and marked; native speakers would rarely say it this way.
Tilfeldig møter jeg henne i byen.
This is grammatically correct but has a focus/emphasis: By chance, I meet her in town. It sounds more literary or stylistic.
Jeg møter tilfeldig henne i byen.
This is not natural; the adverb normally doesn’t split the verb and a short pronoun object like henne.

So: stick to Jeg møter henne tilfeldig i byen as the default.

Why is it i byen and not i en by? What’s the difference?

Norwegian marks definiteness on the noun itself:

en by – a city/town (indefinite)
byen – the city/town (definite)

So:

i en by = in a (some) city
i byen = in the (this/the local) city/town

In the sentence, i byen is similar to English “in town”:

Jeg møter henne tilfeldig i byen.
→ I meet her by chance in town / in the city.

It usually refers to the town/city that is contextually understood (your town, the downtown area, etc.), not just any random city.

When would you say på byen instead of i byen?

I byen and på byen are not interchangeable:

i byen – physically in the town/city (neutral, literal location)
- Jeg jobber i byen. – I work in town.
på byen – an idiom meaning “out on the town,” usually going out to bars, clubs, or partying.
- Vi skal på byen i kveld. – We’re going out (drinking/partying) tonight.

So Jeg møter henne tilfeldig i byen just means you meet her somewhere in town, without the “nightlife” implication that på byen often has.

Can you leave out jeg like in some languages? Is the subject pronoun optional?

No. In standard Norwegian, the subject pronoun is not optional. Norwegian is not a “pro-drop” language like Spanish or Italian.

You must say:

Jeg møter henne tilfeldig i byen. ✅

Leaving out jeg:

Møter henne tilfeldig i byen. ❌
(This might appear in very informal text messages, headlines, or note-taking, but it’s not normal full-sentence grammar.)

You can omit the subject only in special cases, e.g. in coordination where it’s understood:

Jeg går hjem og (jeg) lager middag.
Often spoken/written as: Jeg går hjem og lager middag.

What is the infinitive of møter, and how do you conjugate this verb?

The infinitive is å møte (to meet). It’s a regular verb.

Basic forms:

Infinitive: å møte – to meet
Present: møter – meet(s)
Past: møtte – met
Past participle: møtt – met

Examples:

Jeg møter henne i byen. – I (regularly/now) meet her in town.
Jeg møtte henne i byen. – I met her in town.
Jeg har møtt henne i byen. – I have met her in town.

How would you say the same idea in the past or in the future?

Past (simple):

Jeg møtte henne tilfeldig i byen.
→ I met her by chance in town.

Present perfect:

Jeg har møtt henne tilfeldig i byen.
→ I have met her by chance in town.

Future:

Because tilfeldig means “by chance,” true future sounds a bit paradoxical (you can’t plan a coincidence), but grammatically:

Jeg kommer til å møte henne tilfeldig i byen.
→ I’m going to (end up) meeting her by chance in town.
(Often used about something you think will probably happen.)
Jeg skal møte henne i byen.
Normally means a planned meeting: I am going to meet her in town.
Here you would usually drop tilfeldig, because it’s no longer by chance.

So with tilfeldig, it’s most natural in past or present describing unplanned encounters.

Is the word order Jeg møter henne tilfeldig i byen just a fixed pattern, or does it follow a rule?

It follows general Norwegian word order rules:

Subject – Verb – (Object) – Adverb – Place – Time is a common pattern.
Short pronoun objects usually come right after the verb.
Many adverbs (like tilfeldig) often come after the object.

So:

Jeg (subject)
møter (verb)
henne (object pronoun)
tilfeldig (adverb)
i byen (place expression)

→ Jeg møter henne tilfeldig i byen.

This is not arbitrary; it’s an application of standard S–V–O + adverb + place structure.

What’s the difference between møte, treffe, and støte på in this kind of sentence?

All three can involve “meeting,” but with slightly different flavors.

møte
General verb for meeting, both planned and unplanned.
- Jeg møter henne tilfeldig i byen.
  → I run into her by chance in town.
treffe
Often more like “meet / encounter / come across,” sometimes a bit more formal or literary, and it also means “to hit (a target).”
- Jeg treffer henne tilfeldig i byen.
  Also understandable as “I happen to meet her in town,” but møte is more common here in everyday speech.
støte på
Literally “bump into / come across,” emphasizes the accidental aspect.
- Jeg støter på henne i byen.
  → I bump into her in town.
  You often don’t need tilfeldig here, because støte på already implies chance.

In your original sentence, møte is the most neutral and common choice.