Location with 在

在 (zài) is one of the most versatile words in Chinese. At the HSK 1 level, it has two main uses. First, it works as a preposition meaning "at" or "in," placed before the verb to indicate where an action happens: "我在家吃饭" (wǒ zài jiā chī fàn, "I eat at home"). The structure is Subject + 在 + Place + Verb.

Second, 在 can function as the main verb of a sentence, meaning "to be at" or "to be located." "他在学校" (tā zài xuéxiào) means "He is at school." In this case, there is no other verb — 在 itself tells you about the subject's location. To ask where something is, use 在哪儿 (zài nǎr) or 在哪里 (zài nǎlǐ): "你在哪儿？" (Where are you?).

A common point of confusion: when 在 is used as a preposition (before another verb), the location phrase must come before the verb, not after it. "I study at school" is "我在学校学习," not "我学习在学校." This follows the general Chinese rule that modifying information comes before the action it modifies.