For the essential and existential verbs “to be” and “to have,” the forms of the imperfective are equivalent to those of the present. For the perfective past however, there are special forms. The following full verbs are used in the construction of the (perfective) past:

• ཆགས་ “To become”
• བྱེད་ “To do”
• བསྡད་ “To stay”
•  བྱུང་ “To happen,” “to obtain”

All these verbs correspond to the (perfective) past tense of the verbs ཡིན་ “to be” and ཡོད་ “to have.”