我想要一辆自行车用英文怎么说

You can say "I want a bicycle" in Engpsh.

The origin of the word "bicycle" is from the French word "bicyclette" which was derived from the Latin word "bi" meaning "two" and "cycle" meaning "a wheel."

Example sentences:

Can you recommend a good place to buy a bicycle?
(你能推荐一个买自行车的好地方吗？)
I need to buy a bicycle for commuting to work.
(我需要买一辆自行车，以便上下班。)
I prefer riding a bicycle to driving a car.
(我更喜欢骑自行车而不是开车。)