I know that most of verbs can be transformed into noun or thing, which does the action.
But why are there many words that stay as they are and the suffix “er” cannot be attached to them.
For instance,
Teach ———-> teacher
Seek—————> seeker
Kill——————> killer
But the following noun stay as they are
- Judge————> judge (the person who judge)
- Guide ————> guide (the person who guide)
- Delegate ———> delegate (the person who is delegated)
Why these nouns, for example, don’t turn into:
- 1) judger
- 2) guider
- 3) delegator
Is there any rule to follow to determine whether a verb takes er or stays as it is to convey the meaning of a person doing that specific job or action?