The Basic Pattern
In English, we use the adverb "not" as our primary way to make a verb negative. The sentence "I'm watching a movie" becomes "I'm not watching a movie," and nothing changes, except for that one word, yet the meaning of the sentence is exactly the opposite. French follows the same basic pattern, except that there are two words we must use. Here is the basic pattern of a French sentence:
sujet + verbe + complément
The sujet (subject) and verbe (verb) are the main parts of the sentence, and exist in every single one. The complément (similar to the English predicate) contains extraneous information, and for the purpose of making a verb negative, can be ignored, leaving us with only the sujet and the verbe. To make a verb negative in French, we add two parts, ne and pas. They are both adverbs, and you need both parts to make the sentence negative correctly. The first, ne, is more of a marker, indicating that the sentence is negative. It does not have a direct translation in English, as we only use one adverb in our negations. The second, pas, translates to "not," and as we will see later, can be replaced by other words to create sentences with "never, nobody, and nothing," as well. Here is how these parts are inserted into a sentence:
sujet + ne + verbe + pas
The ne always goes before the verb, and the pas (or other negative word) always goes after. One important detail to remember is that, as often is the case in French, if ne is followed by a word that starts with a vowel sound, such as the verb avoir (to have), it is changed to n' instead.