Cannot type some letters on keyboard

Hello All,

I hope your having a good day :). I'm having a problem with my iPhone 4. Last night the t g c and v keys do not work. I Can't tap them, but when I'm turn the phone into landscape mode I can. I left it over night off to see if that would work, it didn't, so I manually restarted it, reset the settings and also turned off iCloud settings (YouTube recommended this).

Any help is hugely appreciated!

Kind Regards,

Mark :)