S. active participle grammar.
The present active participle in Sindarin generally uses the suffix -ol. Tolkien briefly mentioned this suffix in some notes on negation written in 1959:
If the sense is strictly present (and continuative) the continuative participle -ol may be added, úgarol “not now doing or making, idling” (PE17/144).
In addition to úgarol above (= ú + car- + -ol), there are several Sindarin and Noldorin examples of this suffix being used with both basic and derived verbs:
The most likely historical origin of this suffix is a combination of the ancient present continuative verb marker ā followed by the active participle suffix -lā, to produce -āla > -ǭl(a) > -ol.
The translations here are from notes written between the 1st and 2nd edition of The Lord of The Rings (late 1950s or early 1960s, PE17/20). In roughly contemporaneous linguistic notes, Tolkien described tíriel as an “adj. participle” of a verb tiria- or tíria-:
tíria (cf. tĭrith “watch, ward, guard”). In the adj. participial for tíriel, the t > d as usual in Sindarin with t becoming medial; and so after prefixes (PE17/25) [according to Christopher Gilson, the accent mark in the long í was a later addition and the short vowel mark ĭ was added to tĭrith at the same time, indicating a conceptual shift of tiria- >> tíria- in the verb].
A similar explanation was given for míriel:
míriel, adj. or quasi-adverb (in origin a participial form of verb míria, to shine like a mîr or jewel) “like a jewel, shining jewel-like”.
[in a later note] Participial form from S míria- “to sparkle like jewels”. S mîr, Q míre “jewel” appears often: e.g. in míri “gems” I 394; Remmirath “the netted jewels” (Pleiades); and in many personal names as Tar-Míriel, Atanamir etc. (PE17/24).
As indicated by the translations above (“sparkling as jewels”, “afar-gazing”), in the 1st edition of LotR Tolkien seems to have considered these to be present active participles, but sometime before the publication of the 2nd edition of The Lord of the Rings in 1965, Tolkien changed his mind and reframed this formation as a past active participle. He explained the past nature of tíriel in linguistic notes appearing in A Road Goes Ever On (RGEO) published in 1967:
The Elves of Rivendell could only be said to “gaze afar” by yearning. But the actual form in the hymn is palandíriel (past. part.), “having gazed afar”. This is a reference to the palantír upon the tower hills ... The High-Elves (such as did not dwell in or near the Havens) journeyed to the Tower Hills at intervals to look afar at Eressëa (the Elvish isle) and the Shores of Valinor, close to which it lay. The hymn in Vol. I, p. 250, is one appropriate to Elves who have just returned from such a pilgrimage (RGEO/65).
For RGEO, Tolkien gave new translations of the above phrases more focused on the past:
Note the use of the past tense “have looked” in the translation of díriel. There is no shift in the verb tense for míriel, but perhaps it was reconceived as a simple adjective “with light like jewels” instead of a verbal participle.
Also note that RGEO is not the only place Tolkien mentioned a past or perfective active participle for Sindarin. Such a participle also appeared in an explanation of the name Gilthoniel from a draft of a 1957 letter to David Masson:
thoniel is, however, an archaic perfect participle/adjective of THAN, kindle. Gilthoniel = Starkindler (in past) (PE17/82).
Presumably *thāni(y)ela > thǭniel(a) > thóniel or thoniel “having kindled”. This indicates the most likely origin of the past active participle was the (unaugmented) Common Eldarin perfect (e.g. thāniyē, tīriyē) plus the ancient active participle suffix -lā mentioned above.
Another active participle: Another outlier is the participle tiriel “gazing” (with short i) appearing in Sam’s invocation to Elbereth from later in The Lord of the Rings (LotR/729); this invocation is generally considered to be the second half of the A Elbereth Gilthoniel poem mentioned above.
In the first edition of The Lord of the Rings, this phrase appeared with a long í, and presumably in this period tíriel was the ordinary present active participle, as noted above. But by 1965 Tolkien had decided tíriel was a past active participle, and changed the second appearance of this word to a short i. Tolkien explained the distinction between tíriel and tiriel in linguistic notes from the 1967 song cycle A Road Goes Ever On. First Tolkien claimed that the long i in the second appearance of diriel from the 1st edition of The Lord of the Rings was a mistake:
By an error which has escaped my attention in various corrections the i in these words [diriel and tiro] is marked í [in 1st ed. LotR]. It should be short (RGEO/64 in a footnote).
Tolkien’s attribution of this change to an “error” is somewhat disingenuous on his part, since it actually represented a conceptual shift on how participles were formed; in private notes before the publication of the second edition the í was still long (PE17/94). He then elaborated on the precise meaning of diriel with a short i in some notes on the derivatives of the root √TIR:
The stem TIR, “to look at (towards), watch, watch over,” occurs in Q. palantír and in Tirion, “great watch tower”, Vol I, pp. 247, 389, Vol II, p. 204, in S. palandíriel, -dĭriel (with S. change of medial t > d), and tiro (imperative) in Sam’s invocation. As a “divine” or “angelic” person Varda/Elbereth could be said to be “looking afar from heaven” (as in Sam’s invocation); hence the use of the present participle [in another footnote: with short dir] (RGEO/65).
Thus by 1967 Tolkien considered the distinction between tiriel vs. tíriel to be that of present vs. past (active) participles “gazing” vs. “having gazed”. As described by Christopher Gilson in the preface to Parma Eldalamberon #17:
In this printing [2nd ed. LotR] he also changed palan-díriel to palan-diriel and tíro to tiro in Sam’s invocation to Elbereth (II 338f.), reflecting grammatical features of Sindarin that may have emerged in Tolkien’s preparation of notes for The Road Goes Ever On, A Song Cycle ... In “Words, Phrases and Passages” [the main content of PE17 written before the 2nd ed.] palandíriel is explained as containing the participial form tíriel of the verb tíria, and is translated “afar-gazing”, closely parallel to míriel “shining jewel-like”' from the verb míria- (I 250). In the new conception [in RGEO written after the 2nd ed.] palandíriel is an active past-tense participle “having gazed afar” while palan-diriel is the corresponding present participle “gazing afar”, the distinction being marked by the long vowel in the past-tense form and the contrasting short vowel in the present-tense (PE17/7).
The exact motives for this conceptual shift are not clear, but perhaps Tolkien decided that tíriel must be a past form given its clear resemblance to the CE perfect. Tolkien further wanted to retain a present-tense sense for Sam’s invocation to Elbereth, where Sam was asking her to gaze upon him in the present moment. Tolkien was unable to switch to the style of the earlier present participle mentioned above (tirol or tiriol) because it would ruin the rhyme, and so introduced a new present participle form tiriel with a short base vowel and suffixal -el. It is conceivable that this new participle formation is an aorist active participle, as opposed to -ol which is a present continuous or imperfect active participle; see the section on Neo-Sindarin below.
Conceptual Development: There were a couple of examples of what could be active participles in Gnomish from the 1910s:
It’s hard to tell since both -(i)ol and -og were common adjective suffixes in this period. However, ol· “*being” was said to be the active participle of the verb G. na- “be” (GL/58), so some connection between -ol and active participle seems likely.
In the Early Noldorin Grammar of the 1920s, active participles were mostly just the verb tense stem with a suffixal -l. There were Early Noldorin active participles for the present, past and aorist tenses, as well as past imperfect:
There were archaic present/past active participle forms [ON] madel (pl. medil) and mannel (pl. mennil) given on PE13/131, with “modern” present/past participle forms madol and madannel (pl. medennil). The change of ON. madel > later madol hints that the suffix -ol may have been borrowed from derived verbs. The lack of a plural for madol seems to imply its plural and singular forms were the same. These Early Noldorin active participles correspond to later Sindarin participles in the sense that (a) -l is the main marker for the active participle and (b) there are distinct active participles for different verb tenses.
Neo-Sindarin: It has long been the conventional wisdom that (Neo) Sindarin active participles use the suffix -el for basic verbs and -ol for derived verbs. This system can be traced back to David Salo’s 2004 book, Gateway to Sindarin (GS/113-114). A notable feature of Salo’s system is that basic verbs whose stem have the base vowel i and end in consonants n, l, r add an i before the -el, to explain the active participle tiriel mentioned above. Salo’s system is based on the assumption that the tiriel is the active participle of the verb tir- rather than tiria-.
Salo’s analysis was written before the publication of PE17, and thus did not incorporate attested present participles like carol “doing” and cenol “seeing” (appearing in lenited forms garol and genol), nor did it accommodate the fact that tiriel is actually a participle of the derived verb tiria-, not of a basic verb tir-. Nevertheless Salo’s system is very influential despite being based on faulty premises. The only (Neo) Sindarin Grammar I know of that incorporates the carol, cenol participles is Roman Rausch’s Sindarin Grammatik. I personally recommend using the attested -ol suffix for present participles of both basic and derived verbs.
As for the past/perfect active participle, I think the system proposed by David Salo is sound (GS/120-121): the suffix -iel is added to basic verbs, and the base vowel undergoes the vowel lengthening mutation a, e, o → ó, í, ú (and i, u → í, ú), but unlike the past tense the vowel does not shorten: car-, cen-, nor- → córiel, cíniel, núriel. For derived verbs, the suffix -iel replaces the final -a, but vowel lengthening only occurs if the verb does not have a consonant clusters, so góliel “having grown” (from gala-) but aderthiel “having reunited” (from adertha-). Before such clusters, the base vowel would instead undergo internal i-affection as appropriate (a, o → e): lestiel “having listened” (from lasta-), erthiel “having raised” (from ortha-).
In his article on Sindarin - the Noble Tongue, Helge Fauskanger suggested that derived verbs whose stems end in -ia might have a special behavior in the past active participle, in particular they might restore ancient vowels that had undergone i-affection in the verb stem since lengthened vowels were immune to this mutation. Thus the past active participles of beria-, feria-, heria- (< ancient *barya-, pherya-, khorya-) would be bóriel, fíriel, húriel. It is also possible, however, that they would later regularize around the normal vowel lengthening mutation e → í, hence bíriel, fíriel, híriel. For simplicity I recommend assuming such regularization, since these ancient long vowels would not have been preserved in any other verb forms.
Finally, David Salo’s proposed -el participles might be salvageable as an aorist active participle. It seems that Late Quenya (and Early Noldorin) had had present, past and aorist active participles, so perhaps Sindarin did as well. If you use such aorist active participles, the -el suffix should be used for both basic and derived verbs, since our only attested example (tiriel) seems to be from a derived verb (tiria-). In Quenya verbal notes from 1969, the aorist active participle used the suffix -ila with both basic and derived verbs (PE22/155-156). Perhaps the same was true in ancient Sindarin, so that tiryailā > tiriael(a) > tiriel, with ae > e as it often did in unstressed syllables at the end of polysyllables.
For simplicity, though, I recommend sticking to present active participles with -ol and past active participles with -iel in Neo-Sindarin writing. To summarize:
We don’t have very much information on how Sindarin active participles would be used in a sentence. Most Neo-Sindarin writers assuming that the active participle can be used as an adjective where the modified noun is the one performing the described action: i adan norol “the running man”. Likewise the past active participle is specifically for actions completed in the past: i ’wend ’óliel “the having grown (góliel) maiden”. However, unlike other adjectives there is a common assumption that (like Quenya) active participles are not declined into the plural to match the noun: in edain norol “the running men”, in gwind ’óliel “the having grown maidens”.
|tíriel||← tíria||⇒ palan-díriel||✧ PE17/25|
|garol||“now doing or making”||[← car-]||soft-mutation c-mutation||⇒ úgarol||✧ PE17/144|
|garol||“doing”||[← car-]||soft-mutation c-mutation||⇒ rhugarol||✧ PE17/170|
|genol||[← #cen-]||soft-mutation c-mutation||⇒ fergenol||✧ PE17/181|
|diriel||[← tiria-]||soft-mutation t-mutation||⇒ o menel palan-diriel||✧ LotR/729|
|diriel||“gazing”||[← tiria-]||soft-mutation t-mutation||⇒ o menel palan-diriel||✧ RGEO/64|
|-dĭriel||[← tiria-]||soft-mutation t-mutation||✧ RGEO/65|
|tîriel||“having gazed”||[← tiria-]||✧ Let/427|
|díriel||[← tiria-]||soft-mutation t-mutation||⇒ menel-vîr síla díriel||✧ LB/354|
|díriel||[← tiria-]||soft-mutation t-mutation||✧ Let/279|
|díriel||[← tiria-]||soft-mutation t-mutation||⇒ Na-chaered palan-díriel||✧ LotR/238|
|díriel||“(I) have looked”||[← tiria-]||soft-mutation t-mutation||⇒ Na-chaered palan-díriel||✧ RGEO/63|
|díriel||“having-gazed”||[← tiria-]||soft-mutation t-mutation||⇒ Na-chaered palan-díriel||✧ RGEO/64|
|#díriel||[← tiria-]||soft-mutation t-mutation||✧ RGEO/65|
ᴱN. active participle grammar.
|dagol||[← dag-]||✧ PE13/130|
|gwredhol||← gurdh-||✧ PE13/132|
|lhovol||← †lub-||✧ PE13/132|
|lhuol||← †lub-||✧ PE13/132|
|lhofol||← †lub-||✧ PE13/132|
|madol||← #mad-||✧ PE13/127|
|madol||[← mad-]||⇒ au sóg madol, madol û sog||✧ PE13/128|
|madol||[← mad-]||✧ PE13/129|
|madol||← mad-||✧ PE13/131|
|glathrol||“polishing”||← glathra||✧ PE13/126|
|glathrol||← glathra||✧ PE13/126|
|glathrol||[← glathra-]||✧ PE13/129|
|tangadol||← tangad-||✧ PE13/131|
|mennil||[← mad-]||aorist||✧ PE13/129|
|menni(o)l||[← mad-]||aorist||✧ PE13/129|
|dengil||[← dag-]||past||✧ PE13/130|
|manthil||← #mad-||past||✧ PE13/127|
|mainthil||← #mad-||past||✧ PE13/127|
|manthil||[← mad-]||past||⇒ manthil sóg odog, Manthil sóg odog en maint os eneg bhair||✧ PE13/128|
|manthil||[← mad-]||past||✧ PE13/129|
|mainthiol||[← mad-]||past||✧ PE13/129|
|†mannel||← mad-||past||✧ PE13/131|
|madannel||← mad-||past||✧ PE13/131|
|mannel||“having eaten”||← mad||past||✧ PE13/164|
|glathrathil||← glathra||past||✧ PE13/126|
|glathrathil||[← glathra-]||past||✧ PE13/129|
|[glathr]-aithiol||[← glathra-]||past||✧ PE13/129|
|†tangannel||← tangad-||past||✧ PE13/131|
|†mennil||← mad-||past plural||✧ PE13/131|
|medennil||← mad-||past plural||✧ PE13/131|
|†mennil||← mad||past plural||✧ PE13/164|
|medennil||← mad||past plural||✧ PE13/164|
|†tengennil||← tangad-||past plural||✧ PE13/131|
|†tengénni||← tangad-||past plural||✧ PE13/131|