We make most of our mechanical mistakes in four areas: grammar, punctuation, usage, and spelling.
None of us need to be walking dictionaries, punctuation guides, or spelling champions. Learn the most common errors, how to avoid them, and where to go for help when you need it.
Most grammatical problems concern agreement and misplaced modifiers. Subject and verbs should agree in number. If the subject (noun or pronoun) is singular, the verb should be singular, too: e.g., “he is walking” is correct; “he are walking” is not, because “are” requires a plural subject (“we”).