Грамматика русского языка. Часть 8. Глагол. Глава 4. Настоящее время глагола, cпряжение. Russian Grammar. Part 8. The Verb. Unit 4. The Present Tense of The Verbs, The Regular Conjugation.

Only the Imperfective Verbs can be used in the Present Tense.

In the Present Tense verbs change for person and number – they conjugate. Each person has its own ending. There are two types of personal endings, in accordance with which verbs fall into:

1-st conjugation
2-nd conjugation

As a base for the Present Tense formation we use part of the Infinitive, for example:
   

The Infinitive	Present Tense stem
знать	зна-
говорить	говор-

1-ST CONJUGATION, REGULAR FORMATION


Many Russian 1-st conjugation verbs are conjugated on the pattern of знать (vowel stem):

я знаю	мы знаем
ты знаешь	вы знаете
он, она знает	они знают

The 1-st conjugation (“e” conjugation) comprises the verbs ending in ать, ять, еть, овать, евать, нуть, ти, чь.