An impersonal verb for “to dream” based on the root √OLO-S, so that presumably the putative subject would be in the dative: óla nin “[it] dreams to me = I dream”. This verb says something interesting about Elvish psychology, in that dreams are seen as things that happen to a dreamer rather than an action of the dreamer themselves. This may be related to the Elvish experience of receiving telepathic visions through dreams, from other Elves or from greater powers.
Conceptual Development: The Gnomish Lexicon of the 1910s has a verb G. oltha- that could likewise be used in an impersonal construction with the dative to mean “I dream” (GL/62).
An a-verb ola- appeared with the gloss “grow” in the Quenya Verbal System (QVS) of 1948 (PE22/113, 125), replacing ᴹQ. ala- of the same meaning (PE22/113 note #80). In the same document Tolkien coined a distinct basic verb ᴹQ. ol- “become” (PE22/113). Various other inflections throughout the document belonged to one or the other of these verbs. There are glosses indicating that Tolkien was not entirely certain of the distribution of meaning between the two, however. For example, he had ᴹQ. olinwa (not ✱olanwa) with the sense “fully grown, adult” (PE22/116). Also ola- was given both a weak and strong past tense: olane “grew, were growing” and óle “grew, finished growing, grew up, became” (PE22/116), as opposed to the past tense of ol- which was olle “became” (PE22/103).
In QVS the perfect form of both verbs were the same: (ol)ólie “it has grown up, it has reached its prime, become” (PE22/103, 116), and such similarity of inflected forms may have been the basis for the confusion of meanings. The perfect form olōlie “has become” reappeared in Common Eldarin: Verb Structure of the early 1950s (PE22/133), and again could be from either verb. However, in that document Tolkien had a primitive a-verb ᴹ✶olā- “become, come into being, turn into (another state)”, appearing along with a restored ᴹ✶galā-, which had the more limited sense “grow (of plants)” (PE22/134).
Q. ala- “grow” continued to appear in Tolkien’s latter writings, but its root was usually connected more specifically to the growth of plants (PE17/25, 135, 153). In the various versions of the Löa Yucainen poem from the 1950s, Tolkien had ólar and ólaner “grew” with long ó and applied to trees (CPT/1296-8). In notes from around 1959, Tolkien had several more words indicating that √OL continued to be the basis of growth-words for people: Q. olmen “growth-year”, Q. olmië “growth” and Q. quantolië “maturity” (NM/84, 119-120).
Neo-Quenya: For purposes of Neo-Quenya, I would use just the a-verb ola- with the sense “grow (up); grow into or become”. It can be used intransitively with people and animals with the sense “grow (up)” as in i Elda olane lintavë “the Elf grew quickly”. For plants, however, I would ala- as the normal word for “grow” (see that entry for discussion). Used transitively, the verb ola- has the sense “grow into or become”, as in i Elda olólie nisse “the Elf has become/grown into a woman”. In this sense it can also apply to inanimate or abstract things: i taure olane ráva yonde “the forest became a lawless region”. Thus ola- refers to the process of growing, maturing and transitioning. If it has a direct object, that object is the thing one grows into or becomes.
Note that this verb is similar in form to óla- “to dream”, but confusion is unlikely since “dream” is an impersonal verb, where the putative subject would be in the dative: óla i Eldan “the Elf dreams, (lit.) dreams [come] to the Elf”, as opposed to i Elda ola lumba “the Elf becomes/grows weary”. To avoid confusion, I would also use ola- “grow, become” only with short rather than long ó.