Early Primitive Elvish
hařa
root. cleave, remain
haða
root. cleave, remain
hara Reconstructed
root. HARA
ðoro
root. sit
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.
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.
A root in the Qenya Lexicon of the 1910s glossed “sit” with derivatives mean “sit” or “seat” (QL/85-86). In the Qenya Lexicon Tolkien gave the root as SORO with ÐORO in parenthesis, but Gnomish cognates like G. dorn “seat” and dortha- “to settle” (GL/30) make it clear ÐORO was the true form of the root. There were a variety of different roots for “sit” in later writings such ᴹ√KHAM or √KHAD.