Contractions are shortened forms of words and phrases. Let’s is the contracted form of let us. An apostrophe is used in place of all omitted letters.

Contractions—such as “don’t” instead of “do not”—can make writing and speech sound friendlier. Contractions in dialogue make it more natural sounding and mimic how people actually speak, which helps to keep the reader captivated by the story.

Read your story aloud. Does it sound natural? Contractions create a conversational tone that makes a story easier to read.

If you’re writing a children’s book, look at the dialogue of any recently professionally published children’s book to see if they use contractions. Or if you’re writing an adult fiction novel, see how they handle contractions.

In an older Dr. Seuss book The Cat in the Hat (1957), contractions were not used:
“And this mess is so big
And so deep and so tall,
We can not pick it up.
There is no way at all!”

In a newer Dr. Seuss book If I Ran the Rain Forest (2003), contractions were used:
“Down at the equator
I’ll show it to you.
Your mother won’t mind
very much if I do.”