We all make grammatical mistakes from time to time, both in our everyday speech and in our writing. Writing that is littered with glaring mistakes in grammar and punctuation, however, gives the impression that the writer can’t be bothered and is lazy, sloppy and, perhaps, too stupid to master a few basic rules.
One mistake I notice often is the confusion as to when an apostrophe should be added to a word.
There is no apostrophe when using a possesive pronoun. For example, its, yours, theirs.
However, you do use an apostrophe to indicate that a letter has been omitted. For example it’s is a contraction of it is.
My best wishes, Paul