How do I say 'where is...'?

在哪里 is the simplest way to ask where something is, but it only gets you a location — a point on an imaginary map. In practice, knowing that the subway is “over there” does not help if there are six streets and a highway between you and it.

For actionable directions, switch from 在哪里 to:

• 怎么走 — literally “how to walk.” This gets you street-by-street walking directions. Use this when you are on foot and need to navigate.
• 怎么去 — literally “how to go.” This gets you transport advice: which bus, which subway line, whether you need a taxi.

The three-question sequence for finding anywhere: first 在哪里 (establish the location), then 怎么走 (get walking directions if close), or 怎么去 (get transport instructions if far). Relying only on 在哪里 leaves you with knowledge but no path.