Have/Make Sb Do Sth?

1. your sister is going to do you a favor by picking them up
2. you are forcing your sister to pick them up
3. you are basically asking your sister to pick them up, but not kindly
4. you are politely requesting your sister to pick them up for you
5. like 2, you are forcing your sister to pick them up

To chime in, if you said anything other than #1 or #4, your listener is likely to be quite surprised at your choice of words.

Is the choice of words in 3 that strange?

The last time my sister TOLD me to do something, I was probably about 7 years old. It's just a rather rude was of saying it. These days, she'd ASK me.

So you can "tell" someone to do something for you, depending on the , uh, "context", can't you?

Is it Okay to say, "I'll let my sister pick up the photos for me"?

And what's the difference compared to the others?

Thanks for Gazapo & GG's comments. They help a lot.

Oh yes, context has everything to do with it.

Depending on the circumstances, I'll let her do it would be completely fine. "The photos will be ready about 10, and my sister said she had to go to the store tomorrow morning - I'll let her pick up the photos for me."

Using TELL in the context of telling someone to do something says you that you have the authority over that person to control what they will or will not do. As opposed to: My sister said she'd pick them up for me, but I didn't realize you close early on Tuesdays. I'll tell her to be there before 3:30 In this case, you're not ORDERING her, but letting her know that to complete this task she has already volunteered to do, she needs to be there by 3:30.

That's how I understood it