Forming the Subjunctive: Present and Past

The Subjunctive overview covered when you reach for the subjunctive — reported speech, conditionals, wishes, certain conjunctions. This page is about how to build the forms. Icelandic has two subjunctive tenses, and they are formed by two clean, learnable recipes. The present subjunctive rebuilds the paradigm around a thematic -i. The past subjunctive is built on the preterite-plural stem with an umlaut and the same -i endings. Master those two recipes and you can derive the subjunctive of essentially any verb from forms you already know.

The present subjunctive: thematic -i

The present subjunctive takes the verb's stem and conjugates it with this endings set, in which the -i is the constant signature:

So kalla "call" → kalli, kallir, kalli, köllum, kallið, kalli; fara "go" → fari, farir, fari, förum, farið, fari; taka "take" → taki, takir, taki, tökum, takið, taki. The contrast with the indicative is sharpest in the 3rd person, where the indicative usually has -r (hann fer, hann tekur, hann kallar) but the subjunctive has -i (hann fari, hann taki, hann kalli). That -r versus -i swap is the audible mark of the mood.

vera is irregular: sé

The one verb whose present subjunctive you cannot derive by recipe is vera "be", which is suppletive. Learn it as a block: sé, sért, sé, séum, séuð, séu (the 2sg sért also appears as séir). Because vera is so frequent, this is the single most useful subjunctive paradigm in the language.

Where the present subjunctive hides — and where it shows

Be aware that the present subjunctive does not always look different from the indicative. The 1st-person singular of weak -a verbs is identical in both moods: indicative ég kalla and subjunctive ég kalli differ, but for many verbs the 1pl and 2pl coincide outright — subjunctive köllum, kallið match the indicative köllum, kallið. The mood is therefore reliably visible in the 3rd person (the -r vs -i contrast) and the 2sg (-r vs -ir), but can be invisible elsewhere. This is normal and expected: when the forms coincide, the trigger word (að, ef, þótt) is what tells you the mood, and the verb just goes along. Note too the u-umlaut in the 1pl, where a becomes ö before the -um ending: kalla → köllum, fara → förum, taka → tökum — this happens in both moods and is not a subjunctive marker, just regular Icelandic phonology.

The past subjunctive: preterite-plural stem + umlaut + -i

Here is the rule that unlocks the harder tense. The past subjunctive is built on the preterite PLURAL stem, not the infinitive and not the past singular. You take the stem that shows up in the við/þeir past, apply an umlaut, and add the -i endings (-i, -ir, -i, -um, -uð, -u). This is why the past subjunctive is so tightly bound to a verb's preterite plural:

Trace two of them. Verða has the past plural urðu; umlaut the u to y and add -i → yrði "would become." Finna has the past plural fundu; umlaut u to y → fyndi "found / would find." The strong verb's plural preterite hands you its past subjunctive almost directly — which is exactly why you should learn the preterite plural of strong verbs, not just the singular.

Full past-subjunctive paradigms

Weak verbs: past subjunctive ≈ past indicative

Be honest with yourself about weak verbs: their past subjunctive and past indicative are identical in form, because there is no vowel to umlaut and the endings already match. Kalla gives kallaði in both, elska gives elskaði in both, læra gives lærði in both. The subjunctive force is carried entirely by the trigger (the að, ef, þótt), not by any special ending. So with a weak verb the mood is invisible on the verb itself — you simply have to know the construction requires it.

Why these forms feel alien to English speakers

English lost almost all of its past subjunctive; only were survives clearly ("if I were", "as if she were"). So an English speaker has one fossil and no productive system, and tends to reach for the indicative past everywhere. Icelandic keeps the full machinery alive and audible: væri ≠ var, kæmi ≠ kom, yrði ≠ varð. Because the umlaut visibly changes the vowel, a native ear catches the indicative in a subjunctive slot instantly — Ef ég var ríkur sounds as off to an Icelander as "If I was you" sounds careless to a careful English speaker, only more so, because the language still enforces the distinction.

Common Mistakes

After a subjunctive trigger the 3sg ends in -i, not -r. Kemur is indicative; komi is the present subjunctive.

The past subjunctive umlauts the preterite stem (voru → væri). Forgetting the umlaut leaves a non-form.

When the reporting verb is past (sagðist), the embedded subjunctive moves back to the past subjunctive kæmi, parallel to English "was coming."

Förum is the present indicative/subjunctive 1pl; the past subjunctive (built on fóru) is færum.

A hope is non-factual, so the að-clause takes the present subjunctive verði (from verða).

Key Takeaways

• Present subjunctive: thematic -i across the paradigm (-i/-ir/-i/-um/-ið/-i) — fari, taki, komi, kalli. Wherever the indicative has 3sg -r, the subjunctive has -i. Irregular: vera → sé, sért, sé, séum, séuð, séu.
• Past subjunctive: the preterite-plural stem + umlaut + -i — voru → væri, komu → kæmi, fóru → færi, tóku → tæki, urðu → yrði, fundu → fyndi, höfðu → hefði.
• The umlaut is obligatory: væri, never vari; fyndi, never fundi.
• Use the past subjunctive for counterfactuals (ef ég væri) and for backshifted reported speech under a past reporting verb (sagði að hún kæmi).
• Weak verbs show no umlaut, so their past subjunctive equals their past indicative (kallaði = kallaði); the mood is carried by the trigger alone.