-tavya, -anīya, and -ya

Also known as: the gerundive, the future passive participle, the potential participle, kṛtyāḥ

The suffixes tavya, anīya, and ya all create adjectives, and they all have the same meaning. When added to a root that means “X,” they all mean “should or must be X-ed” or “able to be X-ed.”

Here are some examples:

• त्वया वनं गन्तव्यम्।
  tvayā vanaṃ gantavyam.
  By you, the forest must be gone to. (literal translation)
  You must go to the forest. (natural translation)

• मृगो न हन्तव्यः।
  mṛgo na hantavyaḥ.
  The deer must not be killed.
  

bhāve prayoga

These suffixes often express bhāve prayoga. When they do, they use the neuter case 1 singular:

• योद्धव्यम्
  yoddhavyam
  There should or must be fighting.
  

Here is an example from the Bhagavad Gita:

• कैर् मया सह योद्धव्यम्
  kair mayā saha yoddhavyam
  With whom and me must there be fighting? (literal translation)
  With whom must I fight? (natural translation)

-tavya

Also known as: tavya or tavyat

To add -tavya, we follow the same rules as -tum. As usual, some roots use iṭ and some do not:

• नी → नेतव्य
  nī → netavya
  should or must be led
  

• वन्द् → वन्दितव्य
  vand → vanditavya
  should or must be venerated
  

And as usual, roots that end in consonant sounds might undergo many sandhi changes:

• बुध् → बोद्धव्य
  budh → boddhavya
  

• युध् → योद्धव्य
  yudh → yoddhavya
  

-anīya

Also known as: anīyar

-anīya strengthens the root's vowel to the medium level. Otherwise, it does not cause any special sound changes.

• कृ → करणीय
  kṛ → karaṇīya
  do → should or must be done
  

• दृश् → दर्शनीय
  dṛś → darśanīya
  do → should or must be seen
  

-ya

Also known as: yat, ṇyat, kyap, ...

-ya causes various sound changes. Here are some examples:

• गै → गेयम्
  gai → geyam
  sing → should or must be sung
  

• पा → पेयम्
  pā → peyam
  drink → should or must be drunk
  

• लभ् → लभ्य
  labh → labhya
  obtain → should or must be obtained
  

• शक् → शक्य
  śak → śakya
  be able to → able to be done, possible
  

• सह् → सह्य
  sah → sahya
  endure → endurable
  

• कृ → कार्य
  kṛ → kārya
  do → should or must be done