russian-verb-forms

Conjugate Russian verbs. Compare expected to actual conjugation. Classify similarly conjugated verbs into groups.

Uses data from OpenRussian.org and their database.

Conjugating Verbs (using most basic rules)

• Past Tense

  • remove -ть ending, then add л, ла, ло, ли endings depending on subject

• Present + Imperative Tense

  • verbs fall into one of two categories
  • remove ending (-ть or -ить/-еть)
  • add endings (see table below)

	-ть	-ить/-еть
я	ю	у
ты	ешь	ишь
он, она, оно	ет	ит
мы	ем	им
вы	ете	ите
они	ют	ят
ты command	й	и
вы command	йте	ите

• Reflexive verbs
  • Simply remove the -ся and conjugate like above. Then add the appropriate reflexive endings.

See a longer explanation here

TODO: add rules for participles and gerunds

Expected Conjugation Algorithm in Plain English

1. Set the verb stem equal to the full infinitive
2. Reflexive check; if stem ends in -ся, mark verb reflexive and remove the ending ся from the stem
3. Irregular check; if stem does not end in -ть, mark verb as irregular stem; unable to conjugate, so return early
4. Form past tense; add past tense endings to current stem (-л, -ла, -ло, -ли)
5. Accented ending check; if current stem ends in an accent, update present / future endings so first letter of ending is accented
6. Verb group check;
   • if current stem ends in -и or -е, mark as group two verb and remove и/е from stem
   • else, mark as group one verb
7. Form present/future + imperative tense; add group one/two endings to current stem
8. Reflexive additions; if verb is reflexive, add reflexive endings to all conjugated verb forms