電車を使う必要がありますって英語でなんて言うの？

"have to" means necessary. The requirement is stated after the phrase.

"In order to" explains means "to be able to." In American English, we say "take the train." I hope that this helps. :)

The two sentences you see provided above are great ways to express to your listener that you have to use a train to get to a particular area. In the second sentence you will notice the word access. This means to enter a place or area. This word is appropriate for both formal and informal settings. They would make great additions to your vocabulary.

Native speakers will say like this: “We have to take a train to get there”.
There are lots of other ways to say it, but this one is the most accurate and most commonly used.
Here is an example on how to use this in a conversation:
A: Can you drive us to the airport?
B: I can't. We have to take a train to get there.

The best way is by train or the only way is by train. We you "by" for transportation often: You go by foot , that means walking, or you can go by car or by bike or even by airplane. If the only way to get to the destination is by using the train you can say that one must or has to go by train, it's the only way. If the train is the best option, maybe its the fastest or the most direct, or the most comfortable you can suggest, You should use the train to get there or the best way is by train. Trains in many countries are very convenient and easy, many destinations are best by train.