S. pronunciation and transcription grammar.
Sindarin’s consonant and vowel inventory is described in The Lord of the Rings Appendix E, at least indirectly (LotR/1113-1116). The Sindarin consonants of the 1950s-60s are almost the same as the Noldorin consonants of the 1930s appearing in the Comparative Tables of linguistic development from the 1930s (PE19/18-23), excluding only hw which in Noldorin was chw. The Sindarin consonants are: p, t, c [k]; b, d, g; f (or ph), th, ch; s, h; v, dh; m, n, ñ (IPA [ŋ]); l, r, w; lh, rh, hw. The English consonant “y” [j] does appear in Sindarin, but it is not written that way, since y is a vowel in Sindarin. Instead, it is written i- and only appears at the beginning of words, as in: iant [jant] “bridge”, which in English might be spelled “yant”. Any i appearing before another vowel at the beginning of a Sindarin word is pronounced like English “y”.
The voiced and voiceless stops p, t, c and b, d, g are pronounced as in English, except c is always a hard [k]; it is a beginner’s mistake to pronounce Celeborn like **“Seleborn” rather than “Keleborn”. Unlike Quenya, where Tolkien sometimes switched between k and c (especially in his private writings), in Sindarin this sound is almost always represented with c. The voiceless and voiced spirants s, h; f, th; v are mostly pronounced as in English. One exception is th, which is always voiceless: “th” as in “thin”, never “th” as in “that”. This voiced sound is spelled dh in Sindarin, so the Sindarin spelling of “that” would be dhat. Tolkien sometimes also used þ and ð as alternates to the digraphs th and dh.
Sindarin ch is the sound appearing in Scottish “loch” or German “Bach” and is never pronounced as “ch” in English “church”. Sindarin ph is an alternate spelling of f, appearing at the end of words and sometimes inside of words. That’s because:
F represents f, except at the end of words, where it is used to represent the sound of v (as in English “of”): Nindalf, Fladrif (LotR/1113).
In the interior of words ph usually represents a “long f” as in aphadon “follower” [affadon]. Sometimes, though, Tolkien used f before another consonant to represent a [v] sound, as in the river name Lefnui “Fifth” [levnui] vs. alfirin “immortal” [alfirin]. To counter this, he generally spelled [f] before a consonant with ph as in niphred “pallor”. He also spelled the nasal mutation of p as ph to make the mutation more obvious: Perian “Halfling” → i Pheriain [feriain] “the Halflings” (nasal mutated plural).
The nasals m, n are pronounced as in English. The velar nasal ñ (IPA [ŋ]) is pronounced like “ng” in “sing”, and Tolkien generally represented it as “ng” in his writing. It usually appears as part of the combinations ng and nc, where it does not need any special marking because its pronunciation is clear from the following velar stops g or c. However, it can appear initially as the nasal mutation of g- or the soft mutation of ancient nasalized stop [n]g-, as in di’ñuruthos “in the shadow of death”. Tolkien spelled this di’nguruthos, but some Neo-Sindarin writers (myself included) adopt the spelling ñ from Quenya to make it more distinct from the nasalized stop ng.
The sounds hw, lh, rh are the voiceless equivalents of w, l, r. hw is more or less like English “wh” (IPA [ʍ]). The general consensus is that voiceless lh is like Welsh ll (IPA [ɬ]), a sound English speakers find very difficult, but you can locate videos on the topic on the Internet with a bit of work (search for “how to pronounce Welsh ll”). This voiceless [ɬ] might sometimes appear in the middle of words like mallorn [maɬɬorn], but this is not obvious from the spelling; see the entry on how medial lth became ll for further discussion. You can approximate voiceless rh by blending h with r.
To summarize consonants, they are mostly pronounced like in English except:
Sindarin has 6 vowels: the common i, e, a, o, u as well as y which is always a vowel in Sindarin, never consonantal “y”. The vowels i, e, a, o, u are pronounced like “ee, eh, ah, oh, oo” (IPA [i, ɛ, ɑ, ɔ, u]). The vowel y (IPA [y]) is a pronounced like a French “u” or German “ü”. To produce this sound, round your lips as if you were pronouncing u (“oo”) and then try to produce i (“ee”) without moving your lips.
Sindarin has short (i), long (í) and overlong (î) vowels, with long and overlong represented by an accent ´ and circumflex ˆ respectively; unmarked vowels are short: í is twice as long as i, whereas î is thrice as long. The only difference is in how long the vowel is pronounced, not in the quality of the vowel. Overlong vowels only appear in monosyllables, and you can approximate it by giving the monosyllable “extra stress”. Some monosyllables have only ordinary long vowels (such as nín “my”), probably because they are less stressed than the overlong monosyllables.
Sindarin has six or seven diphthongs. Tolkien only listed the most common six in The Lord of the Rings Appendix E: ai, ei, ui, au, ae, oe. Tolkien described the pronunciation of Elvish diphthongs like this:
All these diphthongs were “falling” diphthongs, that is stressed on the first element, and composed of the simple vowels run together. Thus ai, ei, ... ui are intended to be pronounced respectively as the vowels in English rye (not ray), grey ... ruin; and au (aw) as in loud, how and not as in laud, haw. There is nothing in English closely corresponding to ae, oe ...; ae and oe may be pronounced as ai, oi (LotR/1116).
Thus ai, ei, ui are pronounced like blended “AH-ee, EH-ee, OO-ee”, and similar sounds can be heard in English “eye, play, queen” (except “queen” has a rising diphthong “oo-EE” instead of a falling diphthong “OO-ee”; in Sindarin the emphasis should be on the “OO” bit of the diphthong). The diphthong au is spelled aw at the end of words, and is pronounced like blended “AH-oo” similar to the (British) pronunciation of “loud”. The diphthongs ae, oe are pronounced like blended “AH-eh” and “OH-eh” but neither have good English equivalents, which is why Tolkien suggested they might be pronounced like ai, oi (as in “eye” or “boy”).
The seventh Sindarin diphthong eu is very rare, attested in only two words: leutha- “to pick up” and (maybe) têw “letter”. It likewise has no good English equivalent and is pronounced like blended “EH-oo”.
A more detailed pronunciation guides can be found here:
Conceptual Development: The phonology of Gnomish in the 1910s was somewhat different than later Sindarin, allowing the sounds cw [kʷ] and voiceless nasals nh, mh, ngh (PE15/12). Tolkien soon removed [kʷ] after deciding this sound became [p] in the Early Noldorin of the 1920s. The voiceless nasals lingered until The Etymologies of the 1930s (N. hniof, hmael), at which point they seem to have been abandoned except as historical developments in Old Noldorin and (later) Old Sindarin.
The six basic vowels i, e, a, o, u, y were already present in Gnomish, but diphthongs underwent quite a few changes over the years. The combination io could apparently be a (falling?) diphthong in Gnomish, along with iu (PE15/13). The latter appears in no words and was probably abandoned very early. However, io continued to appear in the Early Noldorin of the 1920s (PE15/64). The diphthong oi was also introduced in Early Noldorin word lists. However, the word ᴱN. boir “heat; hot” has a variant form boer, hinting at the conceptual shift he would adopt later on.
Indeed, in The Etymologies of the 1930s, oi became oe across the board and io survived only in a few weird holdouts like sniuma > N. hniof and beurō > bior > N. beor (Ety/BEW), the latter eventually redefined as a word in the Bëorian language (WJ/218). The diphthong ae likewise first appeared in variant forms in Noldorin word lists from the 1920s such as in ᴱN. dail vs. dael “axe”. The diphthong ae became well established by the 1930s, albeit in partial competition with oe as the Noldorin phonetic development of ai: see the discussion of the phonetic developments of ai and oi for further information.
The last sound to be introduced was hw. In Noldorin of the 1930s this sound mainly appeared as chw- as it is in Welsh, which was presumably a more spirantal [xw] or [xʷ]. Initial hw [ʍ] was not firmly established until The Lord of the Rings Appendix E was written, and even then the sound remained rare.
Element In