In English, the infinitive form of a verb is usually preceded by “to”.
for example, to eat, to play, to wake up, to sleep are all infinitive form of verbs in English.
When these verbs are used in sentences, they get different endings depending upon the tense in which it is used.
for example, in a continuous tense, verbs get suffix -ing (play-ing, jump-ing, laugh-ing)
in simple past tense, verbs get suffix -id.(play-ed, jump-ed,laugh-ed)
This is called inflection. See: Inflection in Hindi
Hindi is no different.
All Hindi verbs have their infinitive form and in their infinitive form Hindi verbs end with a suffix -ना (naa) .
For example: To wake up is उठ-ना (uth-naa)
or To go is जा -ना (jaa-naa).
In the infinitive form of the verb “उठ-ना ” the root of the verb is “उठ” (uth) or
in the infinitive form of the verb “जा -ना “ the root of the verb is “जा” (jaa).
When these verbs are used in different tenses, the root of the verb takes different suffix.(just like English)
The suffix you attach also depends on the gender of the person talking.
for example, in present continuous tense, verbs get suffix -रहा हूँ (rahaa hoon) when a man is speaking and रही हूँ (rahee hoon) when a woman is speaking
(M)मैं उठ रहा हूँ (main uth rahaa hoon) = I am waking up.
(F) मैं उठ रही हूँ | (main uth rahee hoon) = I am waking up.