Manner means the way something is done or how a person behaves; manor is a large estate or its main house. Memory hook: manner has the double n of manners; manor is the grand house with grounds.
The core difference
Manner is a way of doing or behaving, while a manor is a landed estate or its grand house.
- manner — a way of doing something or behaving: Her friendly manner put the nervous patient at ease.
- manner — sort or kind: All manner of people showed up to the festival.
- manor — a large estate or its main house: The family had owned the manor for over three centuries.
How to tell them apart
The two are pronounced almost the same in many accents, which is why they get swapped, especially in phrases such as in a similar manner and manor house. If you can replace the word with way, you want manner. If you mean a big house with grounds, you want manor.
Remember that manners (polite behaviour) is built from manner, so the double n belongs with behaviour. In British slang, your manor is also your home patch.