Translation:He is going to visit
-tembelea (infinitive kutembelea)
1) to visit
(So, the affirmative prefix for future tense is a- "-ta-" for singular third person, indicative; the negative prefix is h - a - "-ta-")
From Wiktionary: https://en.wiktionary.org/wiki/tembelea
Edit: I have put only the tense markers between "", -a- and h- are the other particles of the verb construction.