Help! How do I save new words in T9 mode on my LG Banter?

[CrIstI]

I just upgrade from a phone that was 3 years old. I could type a word or name in once and it would remember it. On this phone, while texting i've even scrolled down the list of suggestions to "add word" and my words still don't stay. Am I missing something? It's taking me forever to text lol. Thanks so much for your help!