Questions & Answers about wǒ ràng tā zài wàimiàn děng wǒ.
What exactly does 让 do here? Is it “let,” “make,” or “tell”?
让 + person + verb phrase is a causative: “have/make/tell (someone) to do something.” In everyday Mandarin it most often means “tell/ask” or “have,” not simply “allow.” For example: 老师让我们做作业。 = “The teacher told us to do homework.” In your sentence, the default reading is “I told/had him wait for me outside.”
Is 让 polite? If I want to be more polite, what should I use?
让 can sound neutral to somewhat commanding depending on context and relationship. To sound politely requestful, use 请: 我请他在外面等我。 To stress permission rather than instruction, use 允许: 我允许他在外面等我。
Can I use 叫 or 使 instead of 让? What’s the difference?
叫 is a near-synonym in speech: 我叫他在外面等我 (very natural). 使 means “to cause” and is formal/literary, better with adjectives or abstract results, e.g., 这件事使我很难过。 Using 使 in your sentence sounds stiff.
Why is 在外面 before 等? Could I say 我让他等我在外面?
Place/time phrases typically go before the verb they modify. 我让他在外面等我 is correct because 在外面 modifies 等. 我让他等我在外面 is unnatural/wrong; 在外面 doesn’t attach properly there.
Do I need 在? Can I say 我让他外面等我?