fylla (to fill; to turn (an age)) | Swedish Grammar

fylla means "to fill" — but its single most useful job for a learner is something English does completely differently: it is the verb for having a birthday and turning an age. In Swedish you don't "become thirty," you fyller trettio. Master that idiom and you can talk about birthdays, ages, and forms like a native.

Principal parts

Infinitive	Present	Preteritum (past)	Supine	Imperative	Group
fylla	fyller	fyllde	fyllt	fyll	Group 2 (-de)

fylla is a Group 2 verb with the voiced -de past. The stem ends in -ll, a voiced sound, so it pulls -de: fyllde. The supine is fyllt — here one l drops before the -t (the cluster llt simplifies to lt in writing, so fyllt, not fylllt). Present is fyll- + -er = fyller, and the imperative is the bare stem fyll (Fyll i blanketten! "Fill in the form!").

Use 1: fill something

The literal sense: to fill a glass, a tank, a room. The thing you fill is a direct object.

Kan du fylla glaset med vatten?

Can you fill the glass with water? fylla + object + med for the contents.

Hon fyllde tanken innan resan.

She filled the tank before the trip. fyllde — the -de past.

Salen var fylld till sista plats.

The hall was filled to the last seat. fylld — the participle, agreeing as an adjective.

Use 2: fylla i — fill in (a form)

With the particle i ("in"), fylla i means "to fill in" — a form, a blank, a box. This is the verb you need at any office or website.

Du måste fylla i blanketten med bläck.

You have to fill in the form in ink. fylla i — particle i, 'fill in'.

Har du fyllt i alla fälten?

Have you filled in all the fields? har fyllt i — perfect of the particle verb.

Use 3: birthdays — fylla år and fylla + a number

Here is the idiom that surprises every English speaker. To say you have a birthday, Swedish says fylla år (literally "fill years"). To say you turn a specific age, you say fylla + the number — no preposition, no "years old."

Jag fyller trettio imorgon.

I turn thirty tomorrow. fyller + the number — no 'years', no preposition.

Min son fyllde fem i förra veckan.

My son turned five last week. fyllde fem — the -de past with the age.

Hur gammal fyller du?

How old are you turning? The standard way to ask which birthday someone is having.

Vi firar att mormor fyller år på lördag.

We're celebrating that Grandma has a birthday on Saturday. fylla år — 'have a birthday', the bare idiom without a number.

The opposite: tömma

The natural antonym of fylla is tömma ("to empty"). You fyller a glass and tömmer it; you fyller i a form and might tömma a folder. They are a tidy pair to learn together.

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The birthday idiom is the key takeaway: fylla år = "have a birthday", and fylla + a number = "turn that age" — Jag fyller trettio, with no år gammal and no preposition. Ask someone's upcoming birthday with Hur gammal fyller du?

Common Mistakes

❌ Jag fyllde trettio år gammal.

Off — with fylla you don't add 'år gammal'. Just fylla + the number: fyller trettio.

✅ Jag fyller trettio.

I turn thirty.

❌ Jag blir trettio imorgon. (less idiomatic for the event)

Understandable, but the natural birthday verb is fylla: Jag fyller trettio imorgon.

✅ Jag fyller trettio imorgon.

I turn thirty tomorrow.

❌ Fyll blanketten.

Incomplete — to fill in a form you need the particle i: fylla i blanketten.

✅ Fyll i blanketten.

Fill in the form.

❌ Jag har fyllat i formuläret. (Group 1 supine)

Incorrect — fylla is Group 2, so the supine is fyllt, not *fyllat. Say har fyllt i.

✅ Jag har fyllt i formuläret.

I have filled in the form.

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