Middle Primitive Elvish
a-
prefix. a-
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Early Quenya
-(u)ma
suffix. a, an; some, certain
-ma
suffix. a; some, certain
-we
suffix. a, an
Qenya
-(u)ma
suffix. some, a, a certain
uma-
prefix. some, a, a certain
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
Sindarin
-a
suffix. -a
-a
suffix. -a
pl1. -on** ** poss. suff. >> heryna
The prefix for singular “some” in Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/99), used in formations like ᴹQ. umallume “some time” and ᴹQ. umas(se) “✱somewhere”. It is probably related to the interrogative root √MA, which is also the basis for (later) ma “something”. See the entry on correlatives for further discussion.