Learn Hardcore Japanese: watasi ha eki de tomodati wo matte imasu. - I am waiting for my friend at the station.

In this sentence は marks 私 as the topic (“as for me”) rather than simply the subject. It signals that the speaker is telling you something about themselves—namely, where and what they’re doing. If you used が, it would emphasize that it’s specifically I (and not someone else) who is waiting, often introducing new information.

What does the particle で after 駅 mean here?

で indicates the location where an action takes place. So 駅で means “at the station,” i.e. the station is the place where the waiting is happening. It’s different from に, which can mark a destination or point in time.

Why do we use を with 友達 even though it’s a person?

を marks the direct object of a transitive verb. Here the verb is 待つ (“to wait for”), and the direct object is the person you’re waiting for—友達を待つ (“wait for a friend”). So using を is completely normal, even with people.

What is 待っています? Why not just 待ちます?

待っています is the progressive or continuous form (て-form + いる) of 待つ. It conveys an ongoing action: “I am in the state of waiting.”

待ちます (non-continuous polite) can simply state a habitual action or immediate future: “I will wait” or “I wait (habitually).”
待っています stresses that you are currently waiting right now.

Can 待っています be shortened in casual speech?

Yes. In casual conversation you often hear 待ってる (dropping い) or even 待ってるよ with rising intonation. In polite writing or speech, though, you’d keep 待っています.

Why is 私 necessary? Can it be dropped?

Japanese often omits pronouns when context is clear. If it’s obvious you’re talking about yourself, you can say simply 駅で友達を待っています and listeners will understand “I am waiting for my friend at the station.” You’d only explicitly say 私 for clarity, contrast, or emphasis.

How do you read 友達? Are there any pronunciation pitfalls?

友達 is read ともだち (tomodachi).

The “とも” is pronounced with a short “o.”
The “だ” is a voiced consonant [da], but sandhi can make it sound a bit softer in rapid speech: [tomodachi].
Avoid over-emphasizing each mora; it should flow evenly.

What’s the basic word order here, and how rigid is it?

Japanese tends to follow Subject–Object–Verb order:
私（S）は駅で友達（O）を待っています（V）。
However, because particles mark roles, you can rearrange topic and object for emphasis (e.g., 友達を駅で待っています) without confusing the listener.

Could you replace 駅で with something like 駅に to mean “at the station”?

No—駅に usually indicates direction (“to the station”) or arrival point, not the place of action. To say “at the station” for the location of waiting, you must use で.