Predictive text word of the day

My phone's predictive text program is.... not great. It's okay, but it's definitely not great. I mean, most the time it gives me the words I'm putting in there. It doesn't have the less common names of people or cities, which isn't surprising. What is surprising, though, is the more common words it misses and the alternative words it offers me.

Like the word "goodnight." All one word? Two words? I try to put it in there as all one word when I'm saying goodnight by text. When I first tried it, this is what it offered me instead:

Goodn4giv.

I never say goodn4giv.

There were other choices: Goodnighu; Goodnighv; Goodnigh8...

...but no Goodnight.