〜せて あげます / 〜せて ください (~sete agemasu / ~sete kudasai) — Let them do / please let me do

Grammar rule (व्याकरण नियम र परिभाषा)

The sentence decides what the causative means — sometimes "make" (an order), sometimes "let" (permission). The easy test: **if the person doing the action wanted it and gains from it, it is "let"**; if they did not want it, it is "make". 子どもを 遊ばせました on its own could be either. To make the meaning clear, add あげます to the て form — 遊ばせて あげました is immediately heard as "I kindly let them play". When you want permission for yourself, say 〜せて ください: 使わせて ください (please let me use it). Note how that differs from 〜て ください — 使って ください = please use it, 使わせて ください = please let me use it. Which to pick? With a boss or a customer, 〜せて ください still sounds a bit direct, so use 〜せて いただけませんか from the next page instead.