Grammar Explanations
AFFIRMATIVE vs NEGATIVE WITH THE NEGATIVE NOT
Is, does and can are third person singular verbs in the affirmative form. To put them in the negative form, simply add the negative word not right after so they become is not, does not and cannot (note that cannot is written as a single word).
These negative forms of verbs also have a contracted form. In order to contract a verb with not, write the verb and not as a single word, take off the o of not and put an apostrophe where the o was. Therefore, is not becomes isn't, does not becomes doesn't and cannot becomes can't. (Note that can't only has one n left from cannot.)