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.
lā
root. LĀ
la
root. no, not; to be not
la(n)srondo
noun. hearer, listener, eavesdropper
la-
prefix. no, not, negative prefix
k’lā
noun. light
glā
noun. radiance
kalat
noun. light
ala
root. no, not; to be not
gū
root. no, not
gālæ
noun. light
gū̆-
interjection. no, not
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.