K so, I just thought of something. You all know how "let's" is the compound for "let us" right? Well, why doesn't it always work?
You look at your friend, and you want to go somewhere, so you say, "Let's go to the park." That makes sense right? "Let's go," "Let us go."
Think of it this way though. If you say "Mom, can you let us go to the park?" It doesn't make sense when you say "Mom, can you let's go to the park."
I mean, they're both "let us," and "let's" is the compound for "let us."
I don't get it.
I might just be stupid right now, but I don't understand how that works.