You may be referring to agent nouns.These nouns are derivatives affixing a suffix to the end of the noun to form or identify a person. An agent noun is a word that identifies a person’s occupation or profession, place of origin or residence, or a device that performs a task, generally signaling its function with a suffix. However, various endings are possible, and as usual in English, there are few absolutes in the spelling of these words.
In other words, agent nouns are usually names for people that perform the action of the verb. Affixing -er to the base form of the verb learn results in the noun learner, meaning someone who learns or adding the -or to interrogate which results in an interrogator referencingone who questions.
Most agent nouns end in either -er (standard) or -or used for words derived directly from Latin, i.e, the word interrogate previously mentioned. A recipient noun denotes a person who receives an action. Recipient nouns usually have the suffix-ee, which technically means one to whom. Agent nouns are more common than recipient ones simply because recipients need agents while agents do not need recipients
Using the word employ gives a perfect example of the difference between the agent and recipient noun.
- Agent noun-Employer
- Recipient noun-Employee
Here are just a few of the thousands of agent nouns in English:
There are far fewer established –ee words. Here are a few of the more common ones: