Theory:

Adding suffixes to words means adding letters at the end of words to form new words. If we add letters like "r", "er", "or" at the end of some words, we get the name of the person doing the activity.
Example:

1. Use \(+\) r \(=\) User (One who uses is called user)

2. Teach \(+\) er \(=\) Teacher (One who teaches is called teacher)

3. Govern \(+\) or \(=\) Governor (One who governs is called governor)

List of words formed by using "r", "er", "or":

No.
Word
 + r / er /or
New word
1
Bake
r
Baker
2
Write
r
Writer
3
Drive
r
Driver
4
Subscribe
r
Subscriber
5
Vote
r
Voter
6
Use
r
User
7
Buy
er
Buyer
8
Watch
er
Watcher
9
Foreign
er
Foreigner
10
Prison
er
Prisoner
11
Teach
er
Teacher
12
Farm
er
Farmer
13
Sail
or
Sailor
14
Operate
or
Operator
15
Act
or
Actor
16
Govern
or
Governor
17
Supervise
or
Supervisor
18
Direct
or
Director