iPhone 7 changes words that were spelled correctly

On my iPhone 7 why even though it is on spellcheck why is my phone so ******* stupid for example I'm spelling see you later and my phone spells it Ciu?! And talk to text that's a completely different story it changes my words that were spelled correctly to words that don't even make sense or ardent even words! Where is the proper grammar!??? And why can't I change the color of my balloons in my text messages to a color I don't have to squint to read?! Green balloons with white letters is NOT EASY TO SEE! Genius' there I swear!

[Re-Titled by Moderator]