tro means "to believe" — and, crucially for English speakers, it is also one of three Swedish verbs that all translate as "think." It is a Group 3 verb (short, infinitive ending in a stressed vowel), conjugating exactly like bo. The real work of this card is the meaning: knowing when "think" is tro (a belief or guess about a fact) versus tycka (an opinion) versus tänka (intend, or use your mind).
Principal parts
| Infinitive | Present | Preteritum (past) | Supine | Imperative | Group |
|---|---|---|---|---|---|
| tro | tror | trodde | trott | tro | Group 3 |
Like bo, the present adds -r to the vowel (tror), the past adds doubled -dde (trodde), and the supine ends in doubled -tt (trott). The doubled consonant marks the shortened vowel — long o in tro, short o in trodde and trott. The imperative tro exists (Tro mig! "Believe me!") but is uncommon outside that set phrase.
Use 1: tro att — a belief or guess about a fact
The most frequent use is tro att ("believe / think that"), expressing a belief or a guess about something you're not certain of. This is the everyday "I think" of guesses and predictions — Jag tror att det regnar ("I think it's raining"). It marks the proposition as not certain knowledge: if you knew, you'd say Jag vet att....
Jag tror att det blir regn i morgon.
I think it'll rain tomorrow. tro att — a guess/prediction, not certain knowledge.
Tror du att hon kommer i tid?
Do you think she'll be on time? A question about likelihood — tro, because it's a guess.
Jag tror det.
I think so. The short answer; tror stands alone with det meaning 'so'.
Use 2: tro på — believe in
With the preposition på, tro means "believe in" — to have faith in the existence, truth or worth of something: a god, a person, an idea, a plan.
Tror du på spöken?
Do you believe in ghosts? tro på + the thing you have faith in.
Hon trodde alltid på mig, även när ingen annan gjorde det.
She always believed in me, even when no one else did. trodde på — the past, faith in a person.
Jag tror på att hårt arbete lönar sig.
I believe that hard work pays off. tro på + att-clause — faith in a principle.
Use 3: past and perfect
The past trodde and the perfect har trott are fully regular Group 3. The past is especially common for a mistaken belief — "I thought (but I was wrong)."
Jag trodde att du redan hade åkt.
I thought you'd already left. trodde — often used for a belief that turned out wrong.
Vi har alltid trott på honom.
We've always believed in him. har trott — the perfect, supine trott after har.
The three "think" verbs: tro vs tycka vs tänka
English crams three different mental actions into one word, think. Swedish keeps them apart, and choosing wrong is the most common B-level error there is. The distinction is reliable:
| Verb | Sense of "think" | Example |
|---|---|---|
| tro | believe / guess (about a fact you're unsure of) | Jag tror att det är öppet. — I think it's open. |
| tycka | have an opinion / find something to be... | Jag tycker att filmen är bra. — I think the film is good. |
| tänka | intend / use the mind / reflect | Jag tänker resa i sommar. — I'm thinking of travelling this summer. |
The test: if you could swap "think" for "believe / guess," use tro. If you could swap it for "in my opinion / I find," use tycka. If you mean "intend to" or "have it in mind," use tänka.
Jag tror att filmen är bra — jag har inte sett den än.
I think the film is good — I haven't seen it yet. A guess, so tro: you're predicting, not judging.
Jag tycker att filmen är bra — jag har sett den tre gånger.
I think the film is good — I've seen it three times. An opinion from experience, so tycka.
Common Mistakes
❌ Jag troar att det regnar. (Group 1 ending)
Incorrect — tro is Group 3. Add only -r to the vowel: tror.
✅ Jag tror att det regnar.
I think it's raining.
❌ Jag troade att du var hemma.
Incorrect — the past doubles the consonant: trodde, not *troade.
✅ Jag trodde att du var hemma.
I thought you were home.
❌ Jag tror att den här soppan är god. (about a soup you're tasting)
Wrong 'think' — for an opinion based on tasting it, use tycker. tro is for guesses.
✅ Jag tycker att den här soppan är god.
I think this soup is tasty.
❌ Tror du i Gud?
Incorrect preposition — 'believe in' is tro på, not *tro i: Tror du på Gud?
✅ Tror du på Gud?
Do you believe in God?
❌ Vi har trodde på honom länge.
Incorrect — after har you need the supine trott, not the preteritum trodde.
✅ Vi har trott på honom länge.
We've believed in him for a long time.
Now practice Swedish
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Start learning Swedish→Related Topics
- Using the Verb ReferenceA2 — How to read the single-verb reference cards and the principal-parts citation system that underpins them. Every Swedish verb is cited as a short chain — infinitive – present – preteritum – supine – (past participle) — because every other form is derivable from those parts. This page decodes one weak verb (tala – talar – talade – talat) and one strong verb (skriva – skriver – skrev – skrivit – skriven), explains the conjugation-group labels (1/2/3/4), and gives a key to everything on a card.
- The Four Conjugation GroupsA2 — Swedish verbs sort into four conjugation classes, identified not by the present tense but by the PAST (preteritum) and supine: Group 1 (talar/talade/talat), Group 2 (ringer/ringde/ringt, köper/köpte/köpt), Group 3 (bor/bodde/bott), and Group 4, the strong verbs (skriver/skrev/skrivit) that change their vowel. Group 1 is so dominant and regular that every new and borrowed verb joins it — so treat it as the default and memorise only the closed list of strong verbs.
- Verb + Preposition GovernmentB2 — Many Swedish verbs demand a specific, unpredictable preposition: tänka på (think about), vänta på (wait for), tro på (believe in), be om (ask for), tycka om (like), längta efter (long for), bero på (depend on). The governed preposition rarely matches English's, and it's unstressed (unlike a particle), so these combinations are vocabulary items you learn as whole units.