It’s important to take your attention to the alphabet structure because it’s the key to unlock your understanding of this beautiful language. Twenty-seven distinct letters are contained in this whole 36-letter alphabet, so in every word we can say or write in the Igbo language, we only use 27 letters. There are times; however, we need to make certain meanings, but the 27 letters on of their own cannot deliver unless one letter tag itself with another (diphthong), for example, ‘g’ for ‘gaa’ = (go) and ‘w’ for ‘wete’ = (bring) and ‘gw’ together for ‘gwakota’ = (mix). Also ‘n’ for ‘nata’ = (receive) and ‘y’ for ‘yiri’ = (wear) and ‘ny’ together for ‘nye’ = (give), etc.
Summary:
Igbo alphabet = 36 letters in all, 27 of which are self-sufficient but can also partner with others in 9 different ways for nine different sounds and meanings. Notice even that letter ‘c’ is the only letter that is not in the alphabet but is married to the letter ‘h’ = ‘ch,’ which can be used in the word ‘Chineke’= (God the creator). 
Oke Iroegbu's Musings 