New Oxford American Dictionary USAGE The adjective everyday, meaning ‘happening or used every day’ or ‘commonplace’ ( everyday activities), is written as one word, whereas the adverb meaning ‘each day, daily’ ( I get up at six every day) is written as two.

I would say that all of the previous answers are correct. Norman is right that you can say either "have" or "take" a shower (both are grammatically correct), but in American English, it is far more common to say "take a shower" (I don't think I've ever heard an American say "have a shower"). The term "have a shower" may be more common in England (and other places outside of the US).

"I take a shower everyday" is the most natural form. There is a difference in meaning for "every day" vs "everyday". Even native speakers can get confused. Every day (two words) means each day. Everyday (one word) means a regular occurrence or used every day (two words).

Either is correct. But not if you use "everyday", it should be two words

I take a shower