In the present, mostly imperfective verbs are used (the exception is covered in the Modal Verbs tutorial). In the future, both imperfective and perfective verbs are used.
- imperfective - used for actions that are repeated or habitual; refered to in general or their entirety; or for actions that last a long time.
- perfective - used for actions that happen one time; where the focus is on a part of the action, such as its completion, lack thereof, beginning, or completion up to a certain point; and for actions that are quick or take a short time.
In the vocabulary list, as in the dictionary, the pairs of verbs are listed in the order: imperfective, perfective.