A subway or metro — an underground railway used for urban commuting and transportation.
毎朝、地下鉄で通勤しています。
I commute by subway every morning.
新しい地下鉄の路線が来年開通する予定だ。
A new subway line is scheduled to open next year.
地下鉄の駅は出口が多くて迷いやすい。
Subway stations have many exits and are easy to get lost in.
ラッシュ時の地下鉄は非常に混雑する。
The subway is extremely crowded during rush hour.