在英语中，坐什么出行通常用 "travel by" 来表示。这个短语的来源源于动词 "travel" 和介词 "by" 的结合。"Travel" 指的是旅行或移动，而 "by" 指的是通过某种方式。因此，"travel by" 的意思就是通过某种方式旅行或移动。

下面是一些例句：

I usually travel by train. (我通常坐火车出行。)
She travels by car when she visits her parents. (她去看望父母时坐汽车出行。)
They travel by plane when they go on vacation. (他们度假时坐飞机出行。)

其他常见的方式包括：

Travel by bus (坐公共汽车出行)
Travel by bike (骑自行车出行)
Travel by boat (坐船出行)
Travel on foot (步行出行)
Travel by taxi (坐出租车出行)

例如：

He always travels by bus to work. (他总是坐公共汽车去上班。)
We love to travel by bike on weekends. (我们喜欢在周末骑自行车出行。)
They took a boat to travel to the island. (他们坐船去了这个岛。)
She travels on foot to the store every day. (她每天步行去商店。)
I'll call a taxi to travel to the airport. (我会叫出租车去机场。)