Good night is used as a parting phrase that is used to say I hope you have a night that is good.
Good night is a phrase that is used as a parting phrase, which means that it is primarily used when people part from each other’s company. The phrase is commonly used to say that ‘I hope you have a good night’. However, the phrase can also imply asking that ‘isn’t this a good night?’.
The phrase ‘good night’ is commonly paired with the phrase ‘good evening.’ In an ideal scenario, when someone meets another during evening, they would greet each other with ‘good evening.’ Then when they parted ways they would part with ‘good night’, irrespective of whether it is still evening or night. This is what common social norms dictate. Good night should never be used before evening as it would seem weird if someone is wishing another good night in the middle of the day.
Many a times, people may use ‘good night’ and instead of meaning anything in relevant to night, all they actually mean to say is ‘bye’ with the ‘good night’ just being implied. Here, ‘good night’ is basically being used due to societal norms that dictate how and when good night should be used, or they may just be saying it out of habit. In any case it is considered polite to use, and the ideal response to ‘good night’ is good night’.
In addition, the phrase ‘good night’ is also used when someone is going to bed. While leaving to go to bed, the person would wish everyone present a good night. If the person is sharing the room or the bed with someone, then they would wish good night just before going to bed. Here, the phrase is used in the context that ‘I hope you have a good night’ and/or ‘I hope you sleep well.’
From this phrase, another version has grown: “Good night, sleep tight, don’t let the bed bugs bite.’ This is just a cute version of saying good night, and is especially used by and for people that are close to each other, rather than just acquaintances.