3. अ (a) is a short, half-open, middle vowel. It is pronounced somewhat like the u in but, or the o in son: अब (ab) 'now', अगर (agar) 'if'.
आ (aa) is a long, open, back vowel. It is pronounced like the a in far or father: आग (ag) 'fire' आप (ap) 'you' (honorific).
इ (i) is a short, close, front vowel. It is pronounced like the i in pin or it. इधर (idhar) 'hither', इक्सठ (iksath) 'sixty-one'.
ई (i) is a long, close, front vowel. It is pronounced like the i in machine or like the ee in heed: ईश (is) 'God', ईख (ikh) 2 'sugar-cane.' ई is, in fact, not only longer, but also closer than इ. Moreover, in uttering it, 'the tongue is in a state of considerable muscular tension', while in uttering इ, the tongue 'the held loosely' (D. Jones). Cf. ऊ below.
उ (u) is a short, close, back, rounded vowel. It is pronounced like the u in put or the oo in book : उधर (udhar) 'thither'. उदय (uday) 'rise'.
ऊ (u) is short, close, back, rounded vowel. It is pronounced like u in June, or oo in fool: ऊपर (upar) 'up, above', ऊन (un) 'wool'. ऊ is, in fact, not only longer but also closer than उ. Moreover, in uttering it, the tongue is in a state of considerable muscular tension, while in uttering उ, the tongue is held loosely. Cf. ई above.
ऋ (r) is short and pronounced as the ri in rip : ऋण (rn) 'debt.' See Note (i) below.
ए (e) is a long, half-close, front vowel. It is pronounced like the a in make or fame (but as a single vowel, as in Scottish English) : एक (ek) 'one'.
ऐ (ai) is a long, half-open, front vowel, It is pronounced some what like the a in bad or glad: ऐब (aib) 'defect, vice', ऐनक (ainak) 'pair of spectacles'.
ओ (o) is a long, half-close, back vowel. It is pronounced like the o in bolt or both (but as a single vowel, as in Scottish English); ओस (os) 'dew', ओह! (oh) 'oh'!
औ (au) is a long, half-open, back vowel. It is pronounced some what like the aw in saw or lawn: औरत (aurat) 'woman', और (aur) 'and, more'.
In Hindi, ऋ is not a vowel sound, but simply the consonant r+the short vowel i (not r+u, as in esome South Indian languages). It is included among vowel letters because it occurs in Sanskrit words where it has the value of a true vowel.
For all practical purposes, इ-ई, उ-ऊ as well as अ-आ may be regarded as pairs of short and long vowels.
ऐ and औ in native Hindi and common Sanskrit words are usually pronounced as simple, long vowels, as explained above. However, in the 'learned' pronunciation of Sanskrit words borrowed into Hindi, or where followed by semi-vowels य (मैया, maiya, mother') and व (कौवा, kauya, crow) respectively, ऐ and औ are made into clear diphthongs and pronounced like अइ (ai) and अउ (au) respectively.
Any vowel, short or long, can be nasalized (spoken through the nose also): अं a, आं a, एं e, ओं o etc.: आंख (akh) 'eye', ईण्ट (it) 'brick', ऊंट (ut) 'camel', ओंठ (oth)2 lip'.