The phrase "are straight" can be replaced by a number of synonyms depending on the context. If referring to a person's sexual orientation, alternatives include "are heterosexual," "identify as straight," or "are attracted to the opposite sex." In a more literal sense, "are straight" can be substituted with "are not crooked," "are upright," or "are aligned." In slang use, "are straight" may be replaced by "are cool," "are okay," or "are good." It is essential to choose the most appropriate synonym to convey the intended meaning accurately in written or spoken language.