A verb expresses an action or a state of being. Swedish verbs only inflect for different tenses and, as such, have four different forms: the infinitive form (the base form), the present tense, the past tense and the past participle form.
Swedish verbs are divided into four conjugation categories:
Group 1
Most Swedish verbs belong to this group. They all end with the letter an in their base form – the present tense ends with –ar, and the past tense ends with -ade.

Group 2
The present tense ends with -er, and the past tense ends with either -de or -te. The ending of the past tense is -te only when the verb's stem ends with one of the following letters: k, p, t, s, x. The verb's stem can be revealed by removing the -er ending from the present tense form.

Group 3
This group consists of verbs containing only one syllable and verbs derived from verbs containing only one syllable. The present tense ending is -r, and the past tense ending is -dde.

Group 4 (strong and irregular verbs)
Strong verbs and irregular verbs are often placed in the same category. They have no uniform conjugation system, so each verb must learn the forms separately.

Note! The present perfect and past perfect tenses are formed by adding a correct form of the verb ha in front of the past participle in the following way:
infinitive titta -> past participle tittat
Present perfect: ha tittat / har tittat = has looked
Past perfect: hade tittat = had looked
EXAMPLE:
Han har tittat på TV ganska mycket. (He has watched quite a lot of tv.)
Linnea, OLS Community Manager – Swedish