Learn Hardcore Swedish: Jag sitter vid datorn hela förmiddagen.

vid means “by/at, next to,” and it’s the most idiomatic choice for being at a workstation: Jag sitter vid datorn.
framför means “in front of” and also works here: Jag sitter framför datorn (emphasizes being in front of the screen).
på means “on (top of)” or “on the computer” (as in stored on it). Jag sitter på datorn would mean you’re literally sitting on the machine, so don’t use på for this context.

Why use sitter instead of är?

Swedish often uses posture verbs (sitter, står, ligger) to describe where someone is and in what position. Jag sitter vid datorn says you’re seated (and likely using it). Jag är vid datorn is possible but more neutral, just “I am at the computer.”

Does sitter in the present tense mean “am sitting” (progressive)?

Yes. Swedish present covers English progressive: Jag sitter = “I am sitting.” You don’t need a separate -ing form.

How do I say “I sit and work at the computer all morning”?

Use the posture-verb-plus-activity pattern: Jag sitter vid datorn hela förmiddagen och jobbar. You can also say Jag sitter och jobbar vid datorn hela förmiddagen.

Why is it datorn (definite) and not en dator?

Swedish often uses the definite form for contextually known things. Vid datorn naturally implies “the/my computer” in the situation. If it’s any random computer, say vid en dator. If you want to be explicit: vid min dator.

What exactly does hela do in hela förmiddagen, and why is it definite?

Hela means “the whole/all of.” With singular nouns, you typically use:

Definite: hela dagen, hela förmiddagen, hela året (“the whole day/morning/year”).
Indefinite alternative: en hel dag/förmiddag, ett helt år (“a whole day/morning/year”). Use helt with indefinite neuter nouns (ett helt år), but hela with definite forms (hela året).

What’s the difference between förmiddag and morgon?

morgon: early morning hours.
förmiddag: late morning, roughly from mid-morning until noon. So hela förmiddagen is “all (of the) late morning (until noon),” not the very early hours. Hela morgonen would be earlier.

Can I start the sentence with the time phrase?

Yes: Hela förmiddagen sitter jag vid datorn. Swedish is a V2 language, so the finite verb (sitter) must be in second position after a fronted element. You can also say Jag sitter hela förmiddagen vid datorn; both orders (place–time or time–place) are acceptable, though the original flows very naturally.

Where does negation go?

After the finite verb: Jag sitter inte vid datorn hela förmiddagen. If you want to negate just the time span, you might rephrase: Jag sitter vid datorn, men inte hela förmiddagen.

How do I say “sit down” in Swedish?

Use sätta sig (not sitta):

“I sit down” = Jag sätter mig.
“I am sitting” = Jag sitter. Different verbs, like English “sit down” vs. “sit.”

How do I put this in the past or future?

Past: Jag satt vid datorn hela förmiddagen.
Present perfect: Jag har suttit vid datorn hela förmiddagen.
Future/intended: Jag ska sitta / Jag kommer att sitta vid datorn hela förmiddagen. Principal parts of sitta: sitta – sitter – satt – suttit.

Any quick pronunciation tips for key words?

Jag: often pronounced like “ya” in casual speech (the final g can be weak/silent).
sitter: double t makes the vowel short: “SI-tter.”
vid: like “veed.”
datorn: stress on DA-, final -rn tends to be a retroflex sound in many accents.
förmiddagen: för- has the rounded vowel (like German ö), primary stress on för: “FÖR-mid-dah-gen.”

Can I add under: under hela förmiddagen?

Yes: Jag sitter vid datorn under hela förmiddagen is fine and emphasizes duration. The under is optional; the original without it is equally natural.

Is hos possible here?

No. Hos is used with people or service providers (hos läkaren = at the doctor’s), not with inanimate objects. Use vid or framför for the computer.

Could I just say I’m working instead of mentioning sitting?

Sure: Jag jobbar vid datorn hela förmiddagen. Using sitter adds the posture nuance and is very idiomatic when the activity happens while seated.