An interjection is a word which expresses some type of
emotion such as surprise, excitement or joy. It is usually at the start of the sentence.
Jeepers, is that the time?
"Jeepers" is used to express surprise. It is an interjection.
John, can you believe the time?
The word "John" is not used to express an emotion.
When a word such as "yes", "no", "well" or "indeed" is used to introduce a sentence, it is classified as an interjection.
Indeed, I agree with your first proposal.
"Indeed" is used to introduce the sentence. It is an interjection.
You must be joking!
There is no interjection in this sentence.
An interjection can only be followed by a comma or an exclamation mark.
Quickly! The tube is coming!
Interjection followed by an exclamation mark - acceptable
Quickly. The tube is coming!
Interjection followed by a full stop - incorrect
An interjection can only be followed by a comma or an exclamation mark.
No, he is not capable of running the team.
Interjection followed by a comma - acceptable
No. He is not capable of running the team.
Interjection followed by a full stop - incorrect