A root Tolkien introduced in the late 1960s with the gloss “suppose”, appearing beside √KE “maybe” (PE22/158). It also had an extended (verbal) form √KWIS “inquire, suppose” in this same document. This late root may have been a restoration of much earlier ᴱ√IQI “request, ask for” from the Qenya Lexicon of the 1910s, whose derivatives had to do with requests and requirements (QL/43).
The roots √KWI and √KE were in competition in the late 1960s as the basis for “if” words in hypthotheticals; see the entry on √KE/EKE for these alternatives.
Neo-Eldarin: For purposes of Neo-Eldarin I think it is best to use √KWI for “if” and √KE for “maybe”; I also think √KWI(S) “inquire” can be used to justify the restoration of some of the derivatives of early ᴱ√IQI, via a hypothetical Neo-Eldarin root ᴺ√IKWI(S) “request, ask for”.
#cíta- ("k")vb. "suppose", cited in the 1st pers. aorist: cítan "I suppose" (VT49:19)