Verb Classes

There are 10 classes of verbs that differ depending on how the root is changed before adding the endings. All ten classes are conjugated either in an active or middle voice. Each of these voice has a different set of endings, and in Classical Sanskrit there is no distinct difference in the meanings between these two voices, just the difference in endings. (The third voice, the passive, has a distinct meaning as in English and will be described below.) A few verbs can be conjugated in both active and middle voices, but most are only conjugated in only one or the other. The 10 classes of verbs with their basic characteristics are as follows:

Class 1: Thematic. The vowel of the root is generally guṇated before endings. The vowels of roots ending in -इ/ई become -अय् and those ending in उ/ऊ become -अव्. Examples are: भू (भवति) – to be, रुह् (रोहति) – to climb, and लभ् (लभते).
Class 2: Athematic. Endings are added directly to the root. The root is guṇated for strong forms, and left unchanged for weak forms. Examples are: इ (एति) – to go, and आस् (आस्ते) – to sit.
Class 3: Athematic. The root is reduplicated according to special rules before adding the endings. Strong forms guṇate the root vowel; weak forms do not. These verbs have a different 3rd person plural active present ending. Examples are: भृ (बिभर्ति) – to bear and धा (दधाति) – to place
Class 4: Thematic. The root is unchanged but a -य- is added to the end of it. Thus, पश् (पश्यति) – to see, and क्रुध् (क्रुध्यते) – to be angry.
Class 5: Athematic. Strong forms add -नो- after the root; weak forms add -नु-. Similar to class 8 verbs. This class has a slightly different ending for the 2nd person singular, imperative active. Examples are: सु (सुनोति) – to press out, आप् (आप्नोति) – to obtain, धू (धूनोति or धूनुते) – to shake.
Class 6: Thematic. Ending are applied directly to the root without change. Examples are विश् (विशति) – to enter, तुद् (तुदति) – to push.
Class 7: Athematic. This class takes what Hart calls a “nasal influx.” This is a nasal added after the vowel but before the final consonant. A -न- (-na- with the implicit vowel) is added to the strong forms, and -न्- (-n- without the implicit vowel) is added to weak forms. (Saṃdhi rules affecting either the -न- or the -न्- are applied.) Thus, युज् (युनक्ति / युञ्जन्ति) – to sacrifice and रुध् (रुणध्ति / रुण्धन्ति).
Class 8: Athematic. Strong forms as -ओ to the root; weak forms add -उ. Since a majority of class 8 verbs end in -न्, this makes them identical in form to class 5. They also have different 2nd person singular imperatives. The one class 8 verb that does not look like class 5 is कृ (करोति / कुरुतः / कुर्वन्ति) – to make and तन् (तनोति / तनुतः / तन्वन्ति).
Class 9: This class adds -ना- to make the strong forms, -नी- to make the weak forms. But the -ई- of -नी- disappears before endings beginning with a vowel. Thus, क्री, buy, makes strong क्रीणा-, weak क्रीणी-. Verbs of this class ending in a consonant take the 2nd imperative active sg. in ान-. Thus, क्री = buy (strong: क्रीणा, weak: क्रीणी) → क्रीणाति, क्रीणीन्ति
Class 10: -अय- is added to the root, which is guṇated in a light syllable and unchanged in a heavy syllable. Medial -अ- is often vṛddhied. Thus, चुर् → चोरायति, तड् → ताडयति, but पीड् → पीडयति