Ever wonder why the dictionary shows different spellings or treatments of words? As an FYI, it’s not because you can just pick whichever you like

According to Merriam-Webster Unabridged Dictionary:  Air-conditioning, when used as a noun, is hyphenated. The house has air-conditioning. Air conditioner, a noun, is open. The air conditioner is on

Should you write thank-you (hyphenated) or thank you (open)? Well, that depends on your meaning. There are actually two ways to write thank you. No,