Modal auxiliaries Vs Primary auxiliaries Primary auxiliaries are be, do, have. They are used to form tenses and to frame short answers. Modal auxiliaries are will, would, may, might, shall, should, can, could, must, dare, need, used, ought. They are used to express moods.
Punctuation marks are signs. We use them in sentences to make the meaning clear or structural portions of writing. They are a standardized simbols such as comma, period, question mark, exclamation point, semicolon, apostrophe, quotation marks, colon, dash, italic, parentheses, brackets and hypen.
Knowing a few simple rules and following a set of guidelines can make a writing experience, in any situation, easier to manage. The rules for all these forms of grammar have evolved over hundreds of years of use.
The most common punctuation symbols are shown in the following table: