1.bicycle是可数名词,基本意思是“自行车,脚踏车”,可指一辆具体的自行车,也可指抽象的交通工具。
2.bicycle常和介词by搭配,表示“骑自行车”,此时介词by不可用其他介词代替,且bicycle不可使用复数。

That bicycle belongs to me.那辆自行车是我的。
The bicycle just brushed me as it passed.自行车从我一旁掠过。
My bicycle is a home product.我的自行车是国产的。
My bicycle has somehow disappeared.我的自行车不知道怎么不见了。
My bicycle had a breakdown.我的自行车出了故障。
Where is your bicycle?你的自行车在哪里?
The little boy was nearly knocked down by the bicycle.那小男孩差点被自行车撞倒。
I got the bicycle at a bargain.我便宜地买到了这辆自行车。
I don't think he can fix the bicycle.我认为他修不好这辆自行车。
May I borrow your bicycle? 我可以借你的自行车吗?
The boy fell off his bicycle and broke his leg.那男孩从自行车上摔了下来,腿摔断了。
He brought in his bicycle.他把自行车推了进来。
I bought the bicycle at a department store.这辆自行车是我在一家百货公司买的。
I must have a look at the bicycle before I pay for it; I don't want to buy a pig in a poke.我得先看一下自行车再去付款,我不想还没有看到东西就把它买下来。
I bought the bicycle years ago.这辆自行车我买了好几年了。
His brother is anxious for a new bicycle.他的兄弟渴望有一辆新自行车。
He is disappointed with his new bicycle.他对他的新自行车很失望。
Don't throw it, it is helpful for us to repair the bicycle.别扔了它,它对我们修自行车有帮助。
As a reward for passing her exams, she got a new bicycle from her parents.作为对她考试及格的奖赏,父母给她买了一辆崭新的自行车。
I asked her to lend me a bicycle, but she was sticky about it.我想借用一下她的自行车,她有点不愿意。
She knows how to ride a bicycle.她会骑自行车。
Jim will knock your block off if he catches you riding his bicycle.吉姆若碰见你骑他的自行车,一定会揍你。
Would you like to go there by bicycle?你愿意骑车去那儿吗?

注意下面三句意思相同:
He went to his office by bicycle.
He went to his office on his bicycle.
He rode his bicycle to his office.
他骑车上班。

他每天骑车去上学。
［误］  He goes to school with bicycle every day.
［正］  He goes to school by bicycle every day.
他骑车回家了。
［误］  He went home by his bicycle.
［正］  He went home by bicycle.
他们骑车去那儿的。
［误］  They went there by bicycles.
［正］  They went there by bicycle.
［析］  by bicycle是固定搭配,表示抽象的“交通方式”,其中by是by means of(以…方法)的意思,不可换用其他介词。其后的bicycle只能用单数,且其前不可加限定词。

bicycle还可用作不及物动词,意思是“骑自行车”。例如：
We bicycled to the beach.我们骑自行车去海滨。