What is the meaning of deviant usage and common error ​

Common Error: Grammatical errors come in many forms and can easily confuse and obscure meaning. Some common errors are with prepositions most importantly, subject verb agreement, tenses, punctuation, spelling and other parts of speech. Prepositions are tricky, confusing and significant in sentence construction.

Deviant Usage: Someone or something that deviates from a norm especially : a person who differs markedly (as in social adjustment or behavior) from what is considered normal or acceptable social/moral/sexual deviants Those who commit crimes also watch TV, go to the grocery store, and have their hair cut.

he is honest with congress and america about the difficulty of the war ahead.

son.