Learn Hardcore Danish: Hun sender en lang email til sin kusine, mens hun ser en serie. - She sends a long email to her cousin while she watches a series.

Sin/sit/sine is the reflexive possessive pronoun, meaning “her own / his own / their own” and it refers back to the subject of the same clause.

sin kusine = her own cousin (the cousin of hun in the same clause)
hendes kusine = her cousin (the cousin of some other female, not the subject)

In the main clause:

Hun sender en lang email til sin kusine
→ The cousin belongs to hun (the one who is sending).

If you said:

Hun sender en lang email til hendes kusine, it would normally be understood as:
→ She sends a long email to another woman’s cousin, not her own.

Who does the second hun (in mens hun ser en serie) refer to? Is it the same person as the first hun?

In most contexts, Danish speakers will understand both hun’s as the same person, unless context clearly forces a different reading.

So the natural interpretation is:

She sends a long email to her own cousin,
while she (the same woman) is watching a series.

However, grammatically it could refer to someone else, because:

sin in the main clause links the cousin to the first hun,
but the second hun is free to refer to either the same or a different woman.

Only the larger context would make a different person clear. Without extra context, listeners assume it’s the same woman.

Why is it en lang email and not et lang email?

In Danish, every noun is either common gender (n-word) or neuter (t-word). The indefinite article agrees with that gender:

en
- common gender nouns
et
- neuter nouns

email is treated as a common gender noun in modern Danish:

en email / en mail / en e-mail
plural: emails or e-mails or mails (spelling varies in real life)

Because email is common gender, you must say:

en lang email
and not
❌ et lang email

Why is it kusine and not a more general word like “cousin”?

Danish distinguishes the gender of the cousin:

kusine = female cousin
fætter = male cousin

There is no single gender-neutral everyday word for “cousin” the way English has. You normally must specify:

min kusine = my (female) cousin
min fætter = my (male) cousin

So sin kusine tells you that the cousin is female.

Why is there a comma before mens in ..., mens hun ser en serie?

mens introduces a subordinate clause (a “while”-clause). Danish comma rules:

You may put a comma before a subordinate clause.
Many people do put a comma there, especially in more formal writing.

So both are seen:

Hun sender en lang email til sin kusine, mens hun ser en serie.
Hun sender en lang email til sin kusine mens hun ser en serie.

The version with the comma is very common and fully correct.

Why does Danish use simple present (sender, ser) instead of something like “is sending / is watching”?

Danish usually uses the simple present tense where English might use a present continuous:

Hun sender en lang email
= She sends / She is sending a long email
mens hun ser en serie
= while she watches / while she is watching a series

There is a construction for “in the process of doing”:

Hun er ved at sende en lang email.
= She is in the process of sending a long email.

But in everyday Danish, simple present is usually enough to express an action happening right now, in general, or repeatedly. Context gives the nuance that English expresses with -ing.

Why is til used in til sin kusine? Could you just say Hun sender sin kusine en email?

With verbs like sende (send), til is the normal preposition for the recipient:

Hun sender en lang email til sin kusine.
= She sends a long email to her cousin.

You can sometimes make a double object construction without til:

Hun sender sin kusine en email.

This is grammatically possible, and some Danes do say it, but:

with til is very common and often sounds more natural and clear,
without til can sound a bit more formal or bookish, depending on context.

If you are unsure, using til with the recipient is always safe:

sende noget til nogen = send something to someone.

Why is the verb in second position: Hun sender en lang email… and not Hun en lang email sender…?

Danish main clauses follow the V2 rule (verb-second):

The first slot is usually the subject (here: Hun).
The finite verb must be in second position (here: sender).
Everything else comes after.

So:

Hun sender en lang email til sin kusine. ✅
Hun en lang email sender til sin kusine. ❌ (word order is wrong)

If you move something else to the front, the verb still stays second:

I dag sender hun en lang email til sin kusine.
(Fronted time phrase I dag, then verb sender, then subject hun)

Does the subordinate clause mens hun ser en serie follow a different word order from the main clause?

Yes. In a subordinate clause (introduced by mens, at, fordi, etc.):

The typical order is Subject – Verb – (Adverb) – Object.

In your sentence:

mens hun ser en serie
→ hun (subject) + ser (verb) + en serie (object)

If you add a sentence adverb like ikke:

Main clause:
Hun ser ikke en serie.
(Subject – Verb – Adverb – Object, but verb is still in 2nd overall position)
Subordinate clause:
mens hun ikke ser en serie.
(Subject – Adverb – Verb – Object)

So, yes, subordinate clauses have a different pattern, especially for where adverbs go.

Can I put the mens-clause at the beginning, like Mens hun ser en serie, sender hun…?

Yes. You can front some or all of the subordinate clause. The main-clause verb must still be second:

Mens hun ser en serie, sender hun en lang email til sin kusine.

Structure:

Fronted subordinate clause: Mens hun ser en serie
Main clause finite verb in second position: sender
Subject of main clause: hun

So you get: Mens hun ser en serie, sender hun … — this is perfectly idiomatic Danish.

Why is it ser en serie for “watching a series”? Isn’t se more like “to see”?

Danish se (ser) covers both English “see” and “watch”, depending on context:

se en film = watch a film
se TV = watch TV
se en serie = watch a series
se noget out of the window = see something

If you want to stress looking actively at something in a physical sense, you might hear:

kigge på = look at
- Hun kigger på serien. = She is looking at the series (more literal, less usual here)

For media (films, series, TV), se is the normal verb in Danish.

What does serie mean here, and how do you make the plural?

serie is a common gender noun (so: en serie) and usually means:

a series, often a TV or streaming series.

In your sentence:

en serie = a (TV) series / show

Plural forms:

singular: en serie
plural: serier (indefinite)
definite plural: serierne

Examples:

Jeg kan godt lide den her serie. = I like this series.
Hun ser mange serier. = She watches many series/shows.

Is email the only natural word? Can you also say mail or brev?

Several options exist in real Danish:

en email / en e-mail – common and easily understood
en mail – very common in everyday speech and writing
et brev – a (physical) letter, usually on paper

So you can say:

Hun sender en lang mail til sin kusine, mens hun ser en serie.
Hun sender et langt brev til sin kusine, mens hun ser en serie.
(now it clearly sounds like a physical letter, and the adjective must agree: et langt brev, because brev is neuter)

In your original sentence, en lang email or en lang mail are the most natural for electronic messages.