Is it barking or barking dog, how is it spelled? - briefly
The correct spelling is "barking."
Is it barking or barking dog, how is it spelled? - in detail
The correct spelling of the word in question is indeed "barking." This term is an adjective derived from the verb "to bark," which describes the characteristic sound made by dogs. When a dog makes this noise, it is said to be "barking." Therefore, when referring to a dog that is making this noise, the correct phrase is "a barking dog."
It's essential to note the placement and use of apostrophes in English grammar. The form "barking'" with an apostrophe would indicate possession, as in "the dog's barking," where the barking belongs to the dog. However, this is not applicable when simply describing a dog that is barking.
To summarize, the correct spelling and usage are:
Understanding these distinctions helps ensure clear and accurate communication in English.