Nouns ending in -er, -or, and -ar
Nouns ending in -er
This ending is the most common. It's usually added to verbs to make nouns with the meaning ‘a person or thing that does something.’ For example: builder, farmer, sprinkler, or beeper.
The -er ending can also be used to form nouns meaning:
‘a person or thing that has a particular quality or form.’ For example: double-decker, two-wheeler, skyscraper.
‘a person belonging to a particular place or group.’ For example: foreigner, prisoner.
'a person concerned with a particular thing.’ For example: jeweler, lawyer, treasurer, mariner.
Nouns ending in -or
Like -er, the ending -or is added to verbs to make nouns meaning ‘a person or thing that does something.’ For example: investigator, decorator, escalator, ventilator.
There are no hard and fast rules as to when these nouns have an -or ending and when they are written -er, but what we can say is that there are fewer such words ending in -or. Here's a list of some of the most important:
There's a smaller group of nouns ending in -or that don't come from verbs:
Some nouns can be spelled with either an -er or an -or ending. For example: adviser/advisor, propeller/propellor, and converter/convertor. Always check in a dictionary if you aren't sure.
Nouns ending in -ar
This ending is used in a few well-known words to mean ‘a person who does something.’ Some of these nouns are related to verbs (e.g., beggar, burglar, liar), but others are not (e.g., scholar, friar, bursar).
The -ar ending is also found in some other common nouns: