Learn Hardcore Swedish: Stress på jobbet påverkar hennes sömn och energi. - Stress at work affects her sleep and energy.

Stress is used here as an uncountable, general concept: stress at work in general.
If you said stressen på jobbet, it would mean the specific stress at work (that we both already know about). Both are grammatically correct, but the original sentence talks about stress as a general condition, so the indefinite form stress fits better.

Why is it på jobbet and not i jobbet for “at work”?

In Swedish, locations like jobbet, kontoret, skolan often use på to mean at:

på jobbet = at work
på kontoret = at the office
på skolan = at school

I jobbet would sound more like in the work / inside the job itself, which is not the usual way to express “at work” in this context. So på jobbet is the natural choice.

What does påverkar mean exactly, and what form is it?

Påverkar is the present tense of the verb påverka = to affect / to influence.

infinitive: att påverka – to affect
present: påverkar – affects / is affecting
past: påverkade – affected
supine: påverkat – (has) affected

Swedish verbs don’t change for person or number, so påverkar is the same for jag, du, hon, de, etc.:
Stress på jobbet påverkar hennes sömn… = Stress at work affects her sleep…

English would say “is affecting” or “affects”. Why is it just påverkar in Swedish?

Swedish only has one present tense form, påverkar, and it covers both:

Stress på jobbet påverkar hennes sömn
= Stress at work affects her sleep (general fact)
= Stress at work is affecting her sleep (right now / these days)

Context decides whether it feels more like a general truth or a current, ongoing situation. You don’t change the form of the verb.

Why is it hennes and not sin for “her”?

Hennes is the non‑reflexive possessive pronoun for a female owner: her.
Sin/sitt/sina are reflexive possessives, and they refer back to the subject of the sentence.

Here, the subject is stress (på jobbet), not the woman. If you wrote:

Stress på jobbet påverkar sin sömn

sin would grammatically refer back to stress, which makes no sense (the stress’s own sleep). Because we mean some woman’s sleep, not the subject’s sleep, we must use hennes.

Do we know if hennes refers to a woman, or could it be neutral?

Hennes specifically refers to a female possessor: her.
For a male possessor, you would use hans = his.

Swedish doesn’t change hans or hennes for grammatical gender of the noun:

hennes sömn, hennes bil, hennes problem
hans sömn, hans bil, hans problem

So hennes tells you the owner is female (already introduced in the wider context).

Why is it hennes sömn och energi and not hennes sömn och hennes energi?

You can say hennes sömn och hennes energi, and it’s grammatically correct, but it sounds heavier and more repetitive.

In Swedish (as in English), you normally say the possessive only once when it’s shared by two nouns:

hennes sömn och energi = her sleep and (her) energy
hennes vänner och kollegor = her friends and (her) colleagues

The second hennes is understood and doesn’t need to be repeated.

Why is there no article before sömn or energi? Why not hennes sömnen or hennes energin?

Both sömn (sleep) and energi (energy) are usually treated as mass/uncountable nouns in this sense.

hennes sömn = her sleep (in general)
hennes energi = her energy (in general)

If you said hennes sömnen or hennes energin, you would be making them definite: her (specific) sleep / that particular energy, which sounds odd here. You might hear the definite forms in more specific contexts, e.g.:

Den här veckan har hennes sömn verkligen blivit sämre.
This week her sleep has really become worse.

What grammatical gender do sömn, jobb, and energi have?

sömn – common gender (en sömn), but mostly used as an uncountable noun, so you rarely see the article.
jobb – neuter (ett jobb), definite jobbet.
energi – common gender (en energi), definite energin.

In the sentence, we see only the definite form jobbet and bare mass nouns sömn and energi.

Why is it jobbet (definite) and not just jobb?

På jobbet is a fixed, natural phrase meaning at work. Swedes almost always say på jobbet, not på jobb, in this sense.

Compare:

Jag är på jobbet. – I’m at work.
Hon börjar på jobbet klockan åtta. – She starts work at eight.

Using the indefinite på jobb would sound unidiomatic in this context.

Could I move på jobbet to the end: Stress påverkar hennes sömn och energi på jobbet?

You can move it, but the meaning shifts slightly:

Stress på jobbet påverkar hennes sömn och energi.
The stress that is at work affects her sleep and energy (in general, not only at work).
Stress påverkar hennes sömn och energi på jobbet.
Stress (in general) affects her sleep and her energy at work (not necessarily her energy in other places).

Swedish word order is flexible, but the position of prepositional phrases often changes what they naturally attach to.

Could I say Stress på arbetet instead of Stress på jobbet?

Yes:

Stress på jobbet – more informal, everyday (jobb = job/work).
Stress på arbetet – more formal, “work” in a slightly more official tone.

Both mean stress at work and are grammatically fine; the difference is mainly style and register.

How do you pronounce påverkar, jobb(et), hennes, sömn, and energi?

Approximate pronunciations (Swedish sounds in CAPS):

påverkar – PÅH-ver-kar
- stress on the first syllable, å like the vowel in English “born” (but a bit tenser).
jobb / jobbet – YOB / YOB-bet
- j like English “y” in “yes”; short o like in “got”.
hennes – HEN-nes
- both e sounds like the e in “get”.
sömn – roughly SÖMN
- ö is like the vowel in British “bird” or French “peur”; the mn cluster is compressed, often sounding like a quick m
  - n.
energi – enehr-GI
- main stress on the last syllable: gi like “ghee”; g is hard (as in “go”).