A verb appearing as infinitive sogo “drink” in The Etymologies of the 1930s under the root ᴹ√SUK of the same meaning (Ety/SUK), with short u becoming o as usual.
Conceptual Development: The same verb G. sog- “drink” appeared in the Gnomish Lexicon of the 1910s (GL/68), but in Tolkien’s earlier writings the root was ᴱ√SOKO (QL/85). The verb ᴱN. sog- also seems to appear in sample sentences in the Early Noldorin Grammar of the 1920s such as ᴱN. manthil sóg odog “✱having eaten he drinks a lot” (PE13/128), but these sentences were not translated.
Neo-Sindarin: In Tolkien’s later writing, the usual Quenya word for “drink” was Q. yul- from the root √YUL, so some Neo-Sindarin writers prefer to coin a neologism ᴺS. ýl- “drink” based on this root. However, I prefer to retain sog- for “drink” in Neo-Sindarin, since the roots √SOK and √SUK also appeared in Tolkien’s later writings, including documents that also had √YUL (PE18/94; VT39/11).
A verb for “to drink” from the 1950s and 60s (PE17/63) based on the root √YUL of the same meaning (PE22/155; WJ/416).