One notable feature of Sindarin adjectives is that they generally appear after the nouns they modify:

The adjectival element usually follows in Sindarin but in certain old elements the older (Quenya) order is maintained, as e.g. with mor- “black” (morgul beside gul-dûr); and in names the order could be shifted for euphonic reasons; so Fanuiðol for normal Dol-fanui (PE17/36).

Quenya preferred the (older) order in which adjectival stems preceded, while in Telerin and Sindarin the adjectival elements often were placed second, especially in later-formed names, according to the usual placing of adjectives in the ordinary speech of those languages. In names however that ended in old words referring to status, rank, profession, race or kindred and so on the adjectival element still in Sindarin, following ancient models, might be placed first (PM/346).

In S. the simple genitive was usually expressed by placing the genitival noun in adjectival position (in S. after the primary noun) (RGEO/67).

The adjective then undergoes soft mutation as appropriate. Examples include:

• Athrad Dhaer “Great [daer] Ford” (WJ/338).
• Bar-goll “Hollow [coll] Dwelling” (WJ/414).
• Cûl Veleg “Big [beleg] Load” (RC/536).
• Eryd Wethrin “Shadowy [gwathren plural] Mountains” (PE17/43).
• Eryn Vorn “Dark [morn] Wood” (RC/lxv).
• Nan Laur “Golden [glaur] Valley” (UT/253).
• Parth Galen “Green [calen] Sward” (LotR/417).
• Talath Dirnen “Guarded [tirnen] Plain” (S/168).
• [N.] i vegli vorn “the black [morn] bear [megli]” (PE22/33).

Tolkien was somewhat inconsistent in the lenition of adjectives, however. For example, there is no mutation in the name Laer Cú Beleg “Song of the Great [beleg] Bow” (S/209). The street name Rath Dínen “Silent Street” is inconsistent with Amon Dîn “*Hill of Silence” (LotR/747), since in Sindarin a noun in a juxtapositional genitive is not lenited. This left Tolkien in a quandary as to the proper forms for “silent/silence”, and he vacillated between dín(en) (PE17/98) and tín(en) (RC/551); this vacillation is also seen in the two forms of the name “Silent Land”: Dor Dínen (S/121) and Dor Dhínen (WJ/333). For the most part, these inconsistencies can be chalked up to slips on Tolkien’s part and probably do not represent conceptual vacillations on the mutation of the following adjective.

One of the examples above, Eryd Wethrin, also demonstrates that Sindarin adjectives are inflected into the plural to agree with their noun. Other examples include:

• Ethraid Engrin “Iron [angren] Fords [athrad]” (UT/264).
• Emyn Duir “Dark [dûr] Hills [amon]” (UT/280).
• Pinnath Gelin “Green [calen] Ridges [pind]” (LotR/771; PE17/97).

The last example shows that the adjective is inflected into the plural when modifying a class plural as well. The plural forms of adjectives follow the same rules as plural nouns. Though we have no examples of it, most Neo-Sindarin writers assume that adjectives in “to be” statements are likewise put into the plural to agree with the subject: in edain delin “the men (are) hidden [dolen]”. As noted in the entry on the copula, one popular Neo-Sindarin practice is to have adjectives in “to be” statements not undergo soft mutation, to make it easier to distinguish “the men (are) hidden” (in edain delin) from “the hidden men” (in edain dhelin).

There is some evidence that quantitative adjectives precede the noun in Sindarin, in particular in the early 1950s phrase: il chem en i Naugrim, untranslated but probably meaning “all (il) hands [cam liquid-mutated plural] of the Dwarves” as suggested by Carl Hostetter (VT50/5, 22-23). It seems the same is true of numbers, based on the (Noldorin) phrase: lheben teil brann “five feet [tal-plural] high” (TAI/150). Similar positioning can be seen in the names Tad-dail “Two Legged” (WJ/388), Lebennin “Five Rivers [Waters]” (LotR/750; RC/274), and Ossiriand “Land of Seven Rivers” (LotR/469). This is especially interesting given that both Common Eldarin and Quenya placed adjectives before the noun, but numbers after (PE21/77, VT49/45); somehow in Sindarin/Noldorin these positions were reversed.

Conceptual Development: The notion that adjectives follow their noun and undergo soft mutation dates all the way back to the Gnomish Grammar of the 1910s, where they were also inflected for number to agree with the noun (GG/15). Likely these are features Tolkien borrowed from Welsh and retained thereafter, though in Welsh adjectives only undergo soft mutation after singular feminine nouns. Note that in the Early Noldorin Grammar of the 1920s, adjectives following plural nouns underwent nasal mutation instead of soft mutation (PE13/124), but there is no evidence of this idea past the 1920s.