yádi ind. (in Veda also yádī, sometimes yadi cit, yadi ha vai, yádī́t, yády u, yady u vai) if, in case that, [RV.] &c. &c. In the earlier language may be joined with Indic. Subj. or Leṭ Pot., or Fut., the consequent clause of the conditional sentence being generally without any particle. In the later language may be joined with Pres. (followed in consequent clause by another Pres., e.g. yadi jīvati bhadrāṇi paśyati, ‘if he lives he beholds prosperity’, or by fut. or by Impv. or by Pot. or by no verb) ; or it may be joined with Pot. (e.g. yadi rājā daṇḍaṃ na praṇayet, ‘if the king were not to inflict punishment’, followed by another Pot. or by Cond. or by Pres. or by Impv. or by fut. or by no verb); or it may be joined with fut. (e.g. yadi na kariṣyanti tat, ‘if they will not do that’, followed by another fut. or by Pres. or by Impv. or by no verb); or it may be joined with Cond. (e.g. yady anujñām adāsyat, ‘if he should give permission’, followed by another Cond. or by Pot. or by aor.); or it may be joined with aor. (e.g. yadi prajā-patir na vapur arsrākṣīt, ‘if the Creator had not created the body’, followed by Cond. or by Pot. or by pf.); or it may be joined with Impv. or even with pf. (e.g. yady āha, ‘if he had said’). There may be other constructions, and in the consequent clauses some one of the following may be used: atha, atra, tad, tena, tatas, tataḥ param, tadā, tarhi, tadānīm. Observe that may sometimes = ‘as sure as’ (esp. in asseverations, followed by Impv. with or without tathā or tena or followed by Pot. with tad), [MBh.]; [Kāv.] &c.; or it may = ‘whether’ (followed by Pres. or Pot. or no verb, e.g. yadi-na vā, ‘whether-or not’, and sometimes kim is added), [ib.]; or it may = ‘that’ (after verbs of ‘not believing’ or ‘doubting’, with Pres. or Pot., e.g. nāśaṃse yadi jīvanti, ‘I do not expect that they are alive’, cf. [Pāṇ. iii, 3, 147], Sch.); or if placed after duṣkaraṃ or kathaṃ cid it may = ‘hardly’, ‘scarcely’, [MBh.]; [R.]; or it may = ‘if perchance’, ‘perhaps’ (with Pot. with or without iti, or with fut. or pres.), [MBh.]; [Kāv.] &c. The following are other combinations: yadi tāvat, ‘how would it be if’ (with Pres. or Impv.)
yadi nāma, ‘if ever’
yadi cet (cet being added redundantly) = ‘if’ (e.g. yadi cet syāt, ‘if it should be’)
purā yadi = ‘before’ (e.g. purā yadi paśyāmi, ‘before that I see’)
yády ápi (rarely api yadi), ‘even if’, ‘although’ (followed by tathāpi or tad api or sometimes by no particle in the correlative clause)
— yadi ca-yady api, ‘if — and if — if also’
yádi — yádi-vā, or yádi vā — yádi vā, or yádi vā — yádi, or yadi vā — vā, or vā — yadi vā, or yad vā — yadi vā, ‘if — or if’, ‘whether — or’
yádi vā — ná vā, ‘whether — or not’
vā — yadi vā — yadi vā-tathāpi, ‘whether — or — or — yet’
vā yadi = ‘or if’, ‘or rather’
yadi vā id. or = ‘yet’, ‘however’.