Informal:
* M kụrụ gị ụra. (M kuuru gi ura) - Literally "I am sleeping for you", meaning "I am missing you."
* Olee ebe ị nọ? M chọrọ gị. (Olee ebe i no? M chooro gi) - "Where are you? I need you." This implies a longing for the person's presence.
* M cheta gị. (M cheta gi) - "I remember you." This can also mean "I miss you" in a more general sense.
Formal:
* M na-eche gị. (M na-eche gi) - "I am thinking of you." This is a more polite way of expressing missing someone.
* M chọrọ ịhụ gị. (M chooro ihu gi) - "I want to see you." This is a more direct way of expressing that you miss someone.
The best way to say it depends on the specific context and your relationship with the person.