lofa ("to promise") is the model citizen of the weak verbs — Class 1, the -aði preterite, no vowel changes, no surprises in the paradigm: lofa, lofaði, lofað. The interest in this verb is entirely in its syntax and a quietly important second meaning. To promise to do something you use lofa að + infinitive; to promise someone something you use a striking double-dative frame — lofa einhverjum einhverju, a dative person and a dative thing side by side. And in a more formal, even religious register, lofa means not "promise" but "praise" (lofa guð "praise God"). This page drills all three. Orthography: the stem is lof-, written with f (pronounced [v] between vowels); the preterite is lofaði with a single ð, and the o never umlauts to ö in the standard paradigm except where the ending forces it (third-plural lofuðu, supine lofað).
Conjugation
Class: weak, Class 1 (the -aði preterite — the largest and most regular weak class, like tala, kalla). Auxiliary: hafa — ég hef lofað "I have promised." The stem lof- is stable; only the regular -a/-aði- endings change.
| Principal parts | |
|---|---|
| Infinitive | að lofa |
| 1sg present | lofa |
| 1sg past | lofaði |
| 3pl past | lofuðu |
| Supine | lofað |
| Person | Present (nútíð) | Past (þátíð) |
|---|---|---|
| ég | lofa | lofaði |
| þú | lofar | lofaðir |
| hann / hún / það | lofar | lofaði |
| við | lofum | lofuðum |
| þið | lofið | lofuðuð |
| þeir / þær / þau | lofa | lofuðu |
| Person | Present subjunctive | Past subjunctive |
|---|---|---|
| ég | lofi | lofaði |
| þú | lofir | lofaðir |
| hann / hún / það | lofi | lofaði |
| við | lofum | lofuðum |
| þið | lofið | lofuðuð |
| þeir / þær / þau | lofi | lofuðu |
| Non-finite & imperative | |
|---|---|
| Imperative (þú) | lofaðu! |
| Imperative (þið) | lofið! |
| Supine | lofað |
| Past participle (m/f/n) | lofaður / lofuð / lofað |
| Middle voice (miðmynd) | lofast — chiefly in lofast "become betrothed / pledge oneself" |
lofa að + infinitive — "promise to do something"
To promise to do something, use lofa að + infinitive. The subject of lofa is also the one who will do the promised action — this is object control in the grammarians' terms, "subject control" more precisely: ég lofa að koma "I promise to come" means I will come. This pattern maps cleanly onto English "promise to," so it's the easy frame.
Ég lofa að koma á morgun, sama hvað gerist.
I promise to come tomorrow, no matter what happens. — lofa að + infinitive (koma); the promiser is the comer.
Hún lofaði að hringja um leið og hún lenti.
She promised to call as soon as she landed. — past lofaði að + infinitive (hringja).
Lofaðu mér að segja engum frá þessu.
Promise me you'll tell no one about this. — imperative lofaðu + dative mér + að-clause; note the dative 'mér' (see next section).
You can also promise that a whole situation will hold, with lofa að + a clause: ég lofa að ég skal laga þetta "I promise (that) I'll fix this." And to promise something to a person while also stating the action, the dative person slots in before að: ég lofa þér að koma "I promise you I'll come."
lofa einhverjum einhverju — the double dative
To promise a person a thing, lofa takes two datives: the recipient (the person) in the dative and the thing promised in the dative — lofa einhverjum einhverju. This is the same ditransitive frame as the verbs of giving and granting, except for the case on the second object: where gefa ("give") takes dative person + accusative thing, lofa takes dative person + dative thing. The cleanest way to see the second dative is to attach an adjective, since adjectives wear the dative ending plainly: ég lofaði henni nýjum síma "I promised her a new phone" — henni (dative "her") + nýjum síma (dative "a new phone," from nominative nýr sími). The double dative is what makes lofa worth a page: it is the cell where learners reflexively put the thing in the accusative, by analogy with gefa, and get it wrong.
Ég lofaði henni nýjum síma í afmælisgjöf.
I promised her a new phone for a birthday present. — lofa + dative person (henni) + DATIVE thing (nýjum síma).
Þau lofuðu okkur miklu en stóðu við fátt.
They promised us a lot but delivered little. — dative person (okkur) + dative thing (miklu).
Ekki lofa börnunum neinu sem þú getur ekki staðið við.
Don't promise the children anything you can't deliver on. — dative person (börnunum) + dative thing (neinu).
The second sense: lofa = "praise"
Quite separately, lofa means "to praise, extol, glorify" — and here it takes a plain accusative object. This sense is formal, liturgical or literary: lofa guð "praise God," lofa einhvern fyrir eitthvað "praise someone for something." It survives most visibly in fixed religious language and in the set phrase guði sé lof "thank God" (literally "to God be praise," where lof is the related neuter noun). Learners meet it in hymns, the Bible, formal eulogies and a few frozen expressions rather than in casual speech, so label it (formal / literary / religious) in your mind and don't reach for it in conversation.
Lofið Drottin, því að hann er góður.
Praise the Lord, for he is good. — lofa 'praise' + accusative (Drottin); (religious/literary register).
Gagnrýnendur lofuðu myndina fyrir frumlega frásögn.
Critics praised the film for its original storytelling. — lofa 'praise' + accusative (myndina), formal/journalistic.
Common Mistakes
❌ Ég lofa þér nýjan síma.
Incorrect — in the 'promise' sense the thing promised is DATIVE, not accusative: 'nýjum síma', not 'nýjan síma'.
✅ Ég lofa þér nýjum síma.
I promise you a new phone.
The signature error, caused by transfer from gefa ("give"), which does take an accusative thing. With lofa (promise), both objects are dative: dative person + dative thing.
❌ Ég lofaði að ég komi.
Mood slip — after 'lofa að' use the plain infinitive (að koma) or, in a clause, the future-ish indicative/subjunctive 'skal koma' / 'kem'; the bare present subjunctive 'komi' here is off.
✅ Ég lofaði að koma. / Ég lofaði að ég myndi koma.
I promised to come. / I promised I would come.
To promise an action, the clean pattern is lofa að + infinitive. If you expand to a full clause, use a future form (ég myndi koma "I would come"), not a bare að ég komi.
❌ Hún lofði mér þessu.
Spelling — the Class-1 preterite is 'lofaði' (with -aði), not '*lofði'.
✅ Hún lofaði mér þessu.
She promised me this.
lofa is weak Class 1: the past is lofaði, plural lofuðu. There is no contracted lofði.
❌ Presturinn lofaði guði.
Wrong case for 'praise' — the 'praise' sense takes the ACCUSATIVE: 'lofa guð'. The dative 'guði' reads as 'promised TO God'.
✅ Presturinn lofaði guð.
The priest praised God.
In the "praise" sense, lofa takes the accusative (lofa guð). A dative guði would push it back into the "promise" frame ("promised to God"), which is not what's meant.
Key Takeaways
- lofa / lofar / lofaði / lofað — a regular weak Class-1 verb (-aði past, plural lofuðu); stable stem, no umlaut surprises.
- lofa að
- infinitive = "promise to do" (subject control — the promiser performs the action): ég lofa að koma.
- lofa einhverjum einhverju = "promise someone something" with two datives — dative person + dative thing (contrast gefa, whose thing is accusative).
- Second sense lofa + accusative = "praise, extol" — (formal / literary / religious): lofa guð, guði sé lof.
- Auxiliary is hafa: ég hef lofað.
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