Ngifanele ngihambe manje

To say you have to do something in Zulu use the verb ukufanela (to have to) - this is used in the -ele form

Abantwana bafanele balungise ekamelweni labo The children must tidy up their room
Nifanele nibize amaphoyisa You (pl.) must call the police

In the impersonal form:

In the case of the third person singular (nouns class1, 1a) the subject concord of the following verb is a- instead of u- eg:

Ngifanele ngihambe manje I must go now
Kufanele ngihambe I must go = it must be that I go
Kufanele ngiyobona I will have to go see