My husband, Matt, was writing an email last week and asked me if he’d use let’s or lets in a sentence. I responded, “Use the apostrophe.”
He asked how I knew. I said, “Well, because you can substitute let us and your sentence still makes sense.”
He responded, “I’m not asking about salad; I want to know about an apostrophe.” (Yes, this is the kind of thing I put up with every day.)
So, let us explore the differences between let’s and lets.
1. to allow or permit.
2. to allow to pass, go, or come.
3. to cause or allow to escape.
4. to grant the occupancy or use of (land, buildings, rooms, space, etc., or moveable property) for rent or hire.
5. to contract for performance: to let work to an electrician.
6. to cause or make: to let someone know.
7. (as an auxiliary used to propose or order): let me see.
noun: a lease.
let’s: a contraction of let us, often used to exhort others to do something: let’s all take the day off.
If you can substitute let us in a sentence and it still makes sense, you would use let’s. (Especially given, according to Matt, it never makes sense to put lettuce anywhere.