The l-form cannot be used just by itself, but is used to form other tenses, one of which is the l-past. To form the l-form of a verb that ends in -и in the dictionary, you need to know whether the verb is imperfective or perfective. Imperfective verbs undergo a change of the final vowel of и>е, and then add one of the following endings to the dictionary form:
- if the subject is masculine, add -л,
- if the subject is feminine, add -ла,
- if the subject is neuter, add -ло,
- if the subject is plural, add -ле.
Perfective verbs fall in several groups. The most numerous are verbs that undergo no change before the endings (above) are added. Some exceptions include забележи 'notice' (which undergoes a change of the final и to а), изброи 'count up' (which has two forms, one with no change of the final vowel and one with a change of the final и to ja), види 'see' (which undergoes a change of the final и to e), се разболи 'get sick', оздрави 'get well', остари 'age, get old' and others (which can have two forms, one with no change, and the second with a change of the final и to e). After the changes of the final vowel in these verbs, the endings (above) are added to form the l-form.