A. J. Lohwater's Russian-English Dictionary of the Mathematical Sciences

have only the perfective, and many, especially verbs adopted from other languages, have the same form in both aspects. (These special situations are not usually mentioned in the dictionary, since nonexistent forms do not have to be translated.) The definition may be repeated for the perfective form when the imperfective and perfective are widely separated in the dictionary. The perfective forms of reflexive or passive verbs are not usually mentioned if the corresponding active forms are given.

A. The Verb 'To Be'

The verb 'to be' (быть) is very important in Russian, as in all languages. Following is the conjugation of быть:

present tense 2
он, она, оно есть		he, she, it is		они суть		they are
future tense
я буду		I will be		мы будем		we will be
ты будешь		you will be		вы будете		you will be
он, она, оно будет		he, she, it will be		они будут		they will be
past tense был, была, было, были
я был, была		I was		мы были		we were
ты был, была		you were		вы были		you were
он был она была оно было		he, it was she, it was it was		они были		they were