"Ah!"
"Awwwww!"
"A-ha!"
etc....
"Xcuse me" and "Xcellent" are interjections that start with the letter X.
'But' is an interjection that begins with the letter 'b'.
Interpolation
Some interjections that start with the letter J include "jeez," "jolly," and "just."
Quiet!
fiddlesticks
"Wow" is an interjection that starts with the letter L.
Kapish is an interjection. It is slang for "Do you understand?"
A few expressions include "Take a breather", "Take the easy way out", "That takes the cake", "There is more than one way to skin a cat", and "Think outside the box." They begin with the letter T.
3 Interjections are Yes! Look! and No! a few other interjections are Stop! Ouch! and Whew! Interjections express emotional excitment.
Joyful interjections like "Yay!", "Wow!", and "Woo-hoo!" Expressive interjections like "Oops", "Ah", and "Oh no!" Attention-grabbing interjections like "Hey!", "Psst!", and "Listen!"
Yes, almost anything can be an interjection,for instance "DOOM!" could even be one.