Emily didn't have any idea how to memorize so many lines.
OR
Emily had no idea how to memorize so many lines.
Both are correct.
The error in the sentence is a double negative. In the sentence, the words "didn't have no idea" are used together, resulting in a double negative. A double negative occurs when two negative words or phrases are used in the same sentence, which can create confusion or ambiguity in the meaning. In this case, the correct formation should be "Emily didn't have any idea how to memorize so many lines." By using the word "any" instead of "no," the double negative is eliminated, and the sentence becomes grammatically correct.
