The infinitive in Russian is the dictionary form of the verb, meaning it’s the form you’ll find in the dictionaries.
In Russian, you’ll find that infinitive verbs can be most often spotted in compound predicates. See these examples:
Дети хотят играть. (Deti khotyat igrat’.) — Children want to play.
Он любит бегать. (On lyubit begat’.) — He loves to run.
Я могу идти? (Ya mogu idti?) — Can I go?
Мне нужно спешить. (Mne nuzhno speshit’.) — I need to hurry.
Вы хотите есть? (Vy khotite yest’?) — Do you want to eat?
Note that in these situations, the first verb of the predicate changes according to the subject of the sentence, while the second one is always infinitive.
The infinitive verb endings are:
-ть is by far the most common one. -ть is by far the most common one. It appears most frequently when the last letter before “т” is a vowel. Verbs with that ending include:
знать (znat’) — to know
петь (pet’) — to sing
слать (slat’) — to send
спать (spat’) — to sleep
называть (nazyvat’) — to name
-ти isn’t as frequent but appears in some basic verbs. It appears in most cases when the last letter before “т” is a consonant
идти (idti) — to go
найти (nayti) — to find
вести (vesti) — to lead; to take (somebody somewhere)
везти (vezti) — to drive (somebody somewhere)
расти (rasti) — to grow
-чь is technically not an ending but part of the root. Verbs that end in “-чь” have no ending:
мочь (moch’) — to be able
печь (pech’) — to bake
беречь (berech’) — to keep
стеречь (sterech’) — to guard
течь (tech’) — to flow; to leak
Keep in mind that in reflexive verbs, the postfix “-ся” or “-сь” goes after the ending. For example:
мыть (myt') — to wash → мыться (myt'sya) — to wash oneself
собирать (sobirat') — to gather → собираться (sobirat'sya) — to get together
учить (uchit’) — to teach → учиться (uchit'sya) — to learn
