The conjugation of verbs is more involved and will take you longer to master than the inflection of nouns. But don't panic - you don't have to learn everything at once.
There are three types of verbs in the Germanic languages. Strong verbs form their past tense with ablaut. Weak verbs form the past tense with dental suffixes. Present-preterite verbs form their present tense like the strong verbs form their past tense. All three groups still exist in English.

English strong verbs:

bite - bit - bitten
ride - rode - ridden
freeze - froze - frozen
choose - chose - chosen
give - gave - given
drink - drank - drunk
take - took - taken

English weak verbs:

love - loved
talk - talked

English present-preterite verbs:

I can - he can (not he *cans)
I will - he will (not he *wills)
How many forms does an Old Norse verb have? If you've worked through the ONfB lessons you are already familiar with the 6 forms of the present tense:
ek tek    vr tkum
 tekr   r taki
hann tekr eir taka
But this is not all of the present tense. This is only the indicative mood. There is a subjunctive mood as well - with another set of forms. It looks like this:
ek taka   vr takim
 takir  r taki
hann taki eir taki
Twelve forms so far. But that isn't all. All the forms above are in active voice. There is a middle voice as well. If you don't already know what a mood and a voice is don't worry. For now all we are thinking about is the forms.


ek tekumk  vr tkumk
 teksk   r takizk
hann teksk eir takask


ek tkumk   vr takimk
 takisk   r takizk
hann takisk eir takisk
That gives us 12 more forms to a total of 24. But we're still not there. Old Norse has two tenses - past and present. The past is also split into indicative and subjunctive, active voice and middle voice. We're up to 48 forms for one verb! And that's still not all. The verbs have an imperative, an infinitive, and participles.
So what do we do? Do you have to memorize more than 50 forms of every single verb? We don't want that. There is a whole lot of regularity in the system. We want to exploit that to work out a general method for extracting all 50+ forms from only a few. It turns out that is enough to memorize three or four forms of each verb. Even better those four forms fall into certain classes. Thus many verbs follow the exact same pattern. When you've learnt to conjugate 'bja; invite' you can also conjugate 'sja; boil', 'hljta; receive', 'skjta; shoot', 'brjta; break' and many more.

Strong verbs

We now turn our attention to the form_1 - form_2 - form_3 - form_4 The present indicative can be extracted from the first form (the infinitive) only according to these rules:
ek form_1 * i-umlaut -a      vr form_1 -a + um
 form_1 * i-umlaut -a + r  r form_1 -a + i
hann form_1 * i-umlaut -a + r  eir form_1
Look complex? Let's try an example. We take the verb 'hljta - hlaut - hlutum - hlotit; receive'. The fyrst form is 'hljta' and we know the i-umlaut of /j/ is //. This enables us to work out the present indicative.
ek hlt vr hljtum
hltr r hljti
hann hltr eir hljta
What about the present subjunctive? That can also be worked out using only the first form.
ek form_1           vr form_1 -a + im
 form_1 - a + ir  r form_1 -a + i
hann form_1 -a + r  eir form_1 -a + i
ek hljtavr hljtim
hljtirr hljti
hann hljtieir hljti
Exercise 1: Work out the present indicative and subjunctive of the following verbs.
bera - bar - bru - borit; carry, bear
fara - fr - frum - farit; go
bta - beit - bitu - bitit; bite
Now we turn our attention to the past tense.
ek form_2      vr form_3 -a + um
 form_2 + st r form_3 -a + u
hann form_2    eir form_3
Our example strikes again.
ek hlaut vr hlutum
hlauzt r hlutu
hann hlauteir hlutu
Note that instead of *hlautst we get *hlauzt. The /tz/ is contract to /z/.
And the past subjunctive. It is derived entirely from form_3.
ek form_3 * i-umlaut + a    vr form_3 * i-umlaut + im
 form_3 * i-umlaut + ir   r form_3 * i-umlaut + i
hann form_3 * i-umlaut + i    eir form_3 * i-umlaut + i
ek hlytavr hlytim
hlytirvr hlyti
hann hlytieir hlyti
And that's all, folks - or almost all. Deriving the middle voice from the active voice is nearly trivial. It involves adding those endings in certain ways.
+ umk    + mk
+ sk     + sk
+ sk     + sk
Things to watch out for:
  • The 'u' of the first person ending overrides an existing 'a' thus ek hljta + umk = ek hljtumk
  • U-umlaut will occur in the first person singular.
  • A dental (t or ) that ends up next to the /s/ gets contracted to 'z'.
Now we are in a position to derive all the forms of the verb 1st ablaut: bta - beit - bitu - bitit tear: slta - sleit - slitu - slitit look: lta - leit - litu - litit crawl: skra - skrei - skriu - skriit 2nd ablaut: bja - bau - buu - boit smear: rja - rau - ruu - roit boil: sja - sau - suu - soit receive: hljta - hlaut - hlutu - hlotit shoot: skjta - skaut - skutu - skotit break: brjta - braut - brutu - brotit 3rd ablaut: bresta - brast - brustu - brostit 4th ablaut: bera - bar - bru - borit skera - skar - skru - skorit nema - nam - nmu - numit 5th ablaut: gefa - gaf - gfu - gefit 6th ablaut: fara - fr - fru - farit wade: vaa - - u - vait (/v/ is always dropped before /o/) load: hlaa - hl - hlu - hlait There are variations within the ablaut rows - but you shouldn't worry about that until you've made some progress memorizing the basic patterns. From these four forms all the other forms of the verb can be derived. Present indicative is formed from the 1st common form. bta: ek bt vr btum btr r bti hann btr eir bta If possible i-umlaut occurs in the singular. bja: ek b vr bjum br r bji hann br eir bja bresta: ek brest vr brestum brestr r bresti hann brestr eir bresta bera: ek ber vr berum berr r beri hann berr eir bera gefa: ek gef vr gefum gefr r gefi hann gefr eir gefa As usually u-umlaut occurs before a u. fara: ek fer vr frum ferr r fari hann ferr eir fara The present subjunctive is also formed from the first kennimynd. ek bja vr bjim bjir r bji hann bji eir bji ek fara vr farim farir r fari hann fari eir fari The preterite indicative is derived from the second and third kennimynd. Awkard clusters sometimes occur in the 2nd person singular. Sometimes they are resolved with a 'z'. Don't worry about it. beit, bitu: ek beit vr bitum beizt r bitu hann beit eir bitu bau, buu: ek bau vr buum baust r buu hann bau eir buu brast, brustu: ek brast vr brustum brastst r brustu hann brast eir brustu gaf, gfu: ek gaf vr gfum gafst r gfu hann gaf eir gfu The past indicative is derived from the third kennimynd with i-umlaut. gfu: ek gfa vr gfim gfir r gfi hann gfi eir gfi