Rule: In English, the word, "depend," is not an adjective (תואר). You are probably used to hearing: it's nice, it's beautiful, (adjectives), but we don't say, "It's depend" because depend is a verb (פועל) - it acts like a regular verb. For example, depend is just like the word, work. We say, it works, she works, etc. (not, it's work or she's work). So we also say, it depends, she depends, (not, it's depend, she's depend).
Rule: After the word, depend, we always use the preposition (מלת יחס) - ON.
Rule: Two negatives in one sentence cancel each other out and transform the meaning into a positive, so that the sentence, "We didn't do nothing last weekend," really means, "We DID something last weekend."
The best way to correct a double negative is to replace the second negative word with, "any."