Dormir is written with u only in some irregular forms of the present indicative, present subjunctive and imperative: Eu durmo, que eles durmam, durma você.
1 verbs follow this model. Below an extract:
To see other models, refer to Model Table
Based on the ending, you can identify features that different verbs have in common. Click on the verbs above to see their conjugation tables and explore their conjugation patterns.