Strong verbs (S)

Strong verbs are like the regular verbs, with only a difference in  

In present tense they all end in -ER

in past tense they all end in -DE/-TE

In supine -T.

(In past participle in -D, -T and -DA or -TA)

Example:
Att sköta - to take care of

Att sköta - sköter - skötte - skött