Okay, so everyone can't be a rocket science or English Professor when it comes to typing. However if one wishes to be clearly understood, a few easy to learn words can go a long way in getting your idea/point across to another. Don't put the burden of what you are trying to say on your audience.
Spelling and grammar can go a long way in getting your point across, legibly. When in doubt, try looking at a dictionary or even Google it; you would be surprised how Google can assist in spelling. Try reading your written sentence out loud as if you were talking face-to-face with a person and see if it makes any sense.