Consonant mutation.

1. Consonant mutation in language refers to the change of one consonant into another under certain conditions.
2. In verbs, consonant mutation can occur on the last consonant, or consonant cluster, of the verb stem. Not every consonant can mutate into another consonant.
3. The rules for consonant mutation in Russian are very simple, and it is important that you learn them early.
4. First, look at the list of consonants that do mutate, and the consonants into which they mutate.
5. Consonants mutate into one of four consonants:

   д, з, г	ж
   т, ц, к	ч
   с, х	ш
   ст, ск	щ

6. Consonant mutation in Russian occurs both in conjugation I and conjugation II verbs.
7. In conjugation I verbs consonant mutation occurs when the stem ends in one of the consonants listed above.
8. Consonant mutation takes place in all forms in the present/future tense. In this example the consonant -с- mutates into the consonant -ш-.

   stem	ending
   пис	-ать
   я пиш	-у
   ты пиш	-ешь
   он, она пиш	-ет
   мы пиш	-ем
   вы пиш	-ете
   они пиш	-ут

9. In conjugation II verbs consonant mutation takes place only in the first person singular (я) form. In the example below the consonant -д- mutates into the consonant -ж-.

stem	ending
приход	-ить
я прихож	-у
ты приход	-ишь
он, она приход	-ит
мы приход	-им
вы приход	-ите
они приход	-ят