My wife's i-phone will not allow her to text properly - some of the letters just won't be put in, and the upper/lower case arrow will not switch from one to the other. Any ideas?
Sounds silly but try powering it off then back on again. This can sometimes clear iPhone glitches.
Have you googled the question? A lot of good help is available on line these days.
If all fails you'll need to visit the Apple Store