Learn Hardcore German: Ich gehe allein in die Stadt.

In German, adverbs like allein (meaning "alone") often come after the verb. The most natural place to put it in this sentence is directly after gehe, though you could also say Ich gehe in die Stadt allein in more colloquial speech. However, Ich gehe allein in die Stadt is more typical and sounds smoother to a native speaker.

Why is it "in die Stadt" and not "in der Stadt"?

The phrase in die Stadt uses the accusative case (die Stadt) because the sentence indicates movement toward a destination. When expressing motion from one place to another, German typically uses the accusative after in. If you were already inside the city and just describing the location, you’d say in der Stadt (dative) to mean "in the city."

Is it correct to say "Ich laufe allein in die Stadt" instead of "Ich gehe allein in die Stadt"?

Yes, it’s correct in terms of grammar, but it changes the nuance. Gehe simply means "go," typically on foot, while laufe also means "run" or "walk," but is often perceived as a bit more active or informal. If your intention is just to say you’re going somewhere by foot, gehe is the safest choice. Laufe is also used for walking, but it can imply a slightly more brisk pace or less formal tone.

What is the difference between "allein" and "einsam"?

Both mean "alone," but allein tends to mean "by oneself" in a neutral way—just stating the fact of being unaccompanied. Einsam carries a connotation of loneliness and isolation. So, allein is factual (you’re simply going alone), while einsam suggests you feel lonely or isolated.