Quenya 

quat-

fill

quat- vb. "fill" (WJ:392), future #quantuva "shall fill" (enquantuva "shall refill") (Nam, RGEO:67) Irrespective of the prefix en- "re", the form enquatuva (VT48:11) displays the expected future tense of quat-. The Namárië form enquantuva seems to include a nasal infix as well, which is possibly an optional feature of the future tense. On the other hand, PE17:68 cites the verb as quanta- rather than quat-, and then the future-tense form quantuva would be straightforward.