Both check in and check-in are the correct spellings. To check in means to register someone when they arrive at a hotel or airport. Check-in is the act of registering and reporting one's presence, typically done at an airport or hotel.
What’s the difference? Yay means yes, and nay means no. You could use yay on its own to express approval or joy, but you would not usually do the same for nay.
Which is the correct spelling? Both are word that exist in English. Although caramel and Carmel have two completely different meanings, carmel (with a lowercase C) is a common misspelling of caramel.
Wether is typically a misspelling of whether. The word whether means “if,” and wether is a castrated ram. Although the spelling is different, the pronunciations are the same.
Do invoke and evoke mean the same thing? Although similar with a slight overlap in meaning, invoke and evoke are two different words that are used in different context.
Till is actually an older version of the word until. Hence, the rumor that till came from until is false. The two synonyms, until and till, can be used interchangeably, as they have the same meaning.
Have you ever wondering what the difference between a "cheque" and "check" was? Cheque is the British English spelling of a written order for an amount of money, and Check is the American English spelling of a written order for an amount of money.