The imperfect (минато определено несвршено време - МОН) of the verb "to be" is made from the root/stem бе-, by adding the already familiar imperfect endings:
- јас -в (= бев)
- ти, тој, таа, тоа -ше (=беше)
- ние -вме (=бевме)
- вие -вте (=бевте)
- тие -а (=беа)
It's useful to remind ourselves of the uses of во and на with the "to be" verb, indicating being at an enclosed location (in a room, in a building, in a tub, in a pool, all expressed with во) vs. being in an open area or something that resembles a mathematical plane (on a field, on a street, on the Earth, etc., all expressed with на) or a non-physical place (work, a concert, a meeting, etc., all expressed with на as well). To review these and other prepositions, go back to the tutorial "4.2.1. Adverbs and Prepositions of Space" (click here).