Many languages soften a request with an extra word or phrase, like please or would you mind, while the verb form itself stays the same. German does something different: it swaps in an entirely different verb form to signal politeness and possibility, called Konjunktiv II.
The core idea: saying Ich will Wasser in the plain present tense (Indikativ) sounds like a blunt demand, almost rude in formal settings. But switching to Konjunktiv II — Ich möchte Wasser or Ich hätte gern Wasser — creates a gentle distance from the request, roughly if it were possible, I would like. Many languages get that same softening effect from a separate polite phrase; German instead builds it directly into the verb's conjugation.
At this level you don't need the full Konjunktiv II system yet — it's also used for wishes and unreal conditional sentences, which come later. For now, three ready-made tools cover daily situations:
möchte, from mögen: for a simple request, as in Ich möchte einen Kaffee. hätte gern: for a request with extra emphasis on the wish, as in Ich hätte gern einen Tisch. würde plus an infinitive at the end of the sentence: a general-purpose pattern that works with almost any verb, as in Ich würde gern nach Berlin fahren.
To turn a statement into a polite question addressed to someone else, use the same verbs with subject and verb inverted: Könnten Sie mir helfen?, meaning could you help me, instead of the blunt imperative Helfen Sie mir!
The most common mistake is reaching for will instead of möchte in restaurants and shops, because it maps more directly onto I want. But Ich will ein Bier sounds jarringly rude to German ears, closer to a child's demand, while Ich möchte ein Bier, bitte is the natural, polite phrasing everyone actually uses. Simple rule: around strangers or in formal situations, avoid will and reach for möchte, würde, or hätte gern instead.