A couple of years ago, a teen flick came out -- Can't Hardly Wait -- that starred Jennifer Love Hewitt and Ethan Embry.
While film was amusing, pulled all right strings and made teeny-boppers cheer on, its title is a case of bad grammar.
Yup, saying, "I can't hardly wait" is bad grammar.
Because it's a double negative.
Consider this sentence: "I don't want no sympathy from you."
Now, let's assume that person who said above statement really doesn't want any sympathy. But sentence implies that what person doesn't want is no sympathy -- which means, he or she wants sympathy. However which way you look at sentence, it is grammatically incorrect.
If person doesn't want any sympathy, he/she should say it either:
I don't want sympathy from you.
I want no sympathy from you.
* The subtle double negatives
Writers and speakers who always strive to write or speak correct English have less problem on double negatives. However, some words used in a negative sense are not recognized as negatives right away. They are sometimes combined with another negative and form a subtle double negative.
Here is a list of these subtle negatives:
seldom but (used as "only"> just merely barely hardly except only scarcely neither ever rarely nothing nowhere
And here are examples of use of double negatives: