～てくれるTo do something for someone (usually you)

ないでください is used to ask someone not to do something in a polite way. It's relatively neutral and can be used with strangers or people of equal status. In contrast, てくれる, when said with a rising question intonation, is a casual and gentle way to ask a favor from someone close, such as a friend or family member. It feels softer and more familiar than standard polite forms.

くれる means 'to give' and is used when someone outside the speaker's group gives something to the speaker or their in-group. For example, プレゼントをくれた means '(someone) gave me a present.' As てくれる, it shows someone did something for the speaker's benefit, as in 日本語を教えてくれた ('(someone) taught me Japanese').

Both use the て form with a giving verb to describe doing a favor. てあげる is used when you or someone close to you does something for someone else, e.g. 友達に日本語を教えてあげた ('I taught my friend Japanese.'). In contrast, てくれる is used when someone else does something for you or someone close to you, e.g. 友達が日本語を教えてくれた ('My friend taught me Japanese.').

てくれる describes someone doing something that benefits you, like 来てくれた ('He/you/they came for me.'), implying that their coming helped you. てくれてありがとう specifically expresses gratitude for the action, e.g. 来てくれてありがとう ('Thank you for coming.'). The base meaning is the same, but one contains an explicit message of thanks.

てくれる shows someone did something for your benefit, like 教えてくれた ('They taught/told me.'). ていただけませんか is a humble and polite way to make a request, e.g. 教えていただけませんか？ ('Would you kindly teach/tell me?'). Both involve benefits for the speaker but differ in tone and usage.

Both express receiving a favor, but from different perspectives. With てくれる, the subject is the giver and they do something for you. With てもらう, the subject is the receiver and they get someone to do something. For example, ケンが教えてくれた frames the action as 'Ken taught/told me.', while ケンに教えてもらった frames it as 'I had Ken teach/tell me.'.

てください is a basic way to express a polite request (e.g., 'Please do...') For example, 食べてください would mean 'Please eat (this).' It is polite and neutral, and can be used with strangers or people equal in status to you. In comparison, てくれる (when used with rising question intonation), is a casual, gentle way of making a request to a close friend or family member.