If you say the US includes 50 states, you're suggesting erroneously that the US is comprised of more than that. Classical refers to the ancient cultures of Greece and Rome. A classical language would be Greek or Latin. You are working alternate days. Alternate, in this case, means intermittent or every other, as in alternate seating.
Alternative suggests a choice between two or more things.
A worker may have the alternative of working a weekend or an evening. The Christian Science Publishing Society. All rights reserved.