disturb") is stör-, and as r is a voiced consonant the past tense ends in -de, that is . For group 2b verbs, the past tense ends in -te and the past participle in -t, -t, and -ta; e.g. the past tense of ("to be called") is . For group 3 verbs, the stem ends in a vowel that is not -a, the infinitive is the same as the stem, the present tense ends in -r, the past tense in -dde, the supine in -tt, and the past participle in -dd, -tt, and -dda. Group 4 regroups strong and irregular verbs, comprising many commonly used verbs. For strong verbs, the stem vowel changes for the past and often the supine, following a definite pattern, e.g. follows the u/y, ö, u pattern (see table below for conjugations). As of lately, an increasing number of verbs formerly conjugated with a strong inflection has been subject to be conjugated with its weak equivalent form in colloquial speech. Irregular verbs, such as ("to be"), follow no pattern. {| class="wikitable" |- style="vertical-align: top" ! Group ! Stem ! Imperative ! colspan="2" | Infinitive ! colspan="2" | Present ! colspan="2" | Preterite/Past ! colspan="2" | Supine ! colspan="2" | Past participle ! English |- style="vertical-align: top" | align="center" | 1 | kalla-| | || — | || -r| || -de| || -t| || -d-t-de| to call |- style="vertical-align: top" | align="center" | 2a | stäng-| | || -a| || -er| || -de| || -t| || -d-t-da| to close |- style="vertical-align: top" | align="center" | 2b | läs-| | || -a| || -er| || -te| || -t| || -t-t-ta| to read |- style="vertical-align: top" | align="center" | 3 | sy-| | || — | || -r| || -dde| || -tt| || -dd-tt-dda| to sew |- style="vertical-align: top" | align="center" | 4 | stryk-| | || -a| || -er| || | || -it| || -en-et-na| to strike outto ironto stroke |- | align="center" | irregular | var-| | || | || | || | || | — || | to be |} Examples of tenses with English translations {| class="wikitable" |- ! Tense ! English ! Swedish |- | Infinitive | to work | (att) |- | Present tense | I work | |- | Past tense, imperfect | I worked | |- | Past tense, perfect | I have worked | |- | future tense | I