jam的复数形式是直接加s，即jams。jam可作名词和动词两种词性，基本含义为“果酱”、“堵塞”、“卡住”、“不能动弹”、“塞进”、“干扰”、“即兴演奏”、“使劲往某处挤”。

jam可作名词和动词，意为果酱;拥挤;堵塞;卡住(因而发生故障)；使劲(往某处)挤(或压、塞);(使)卡住，不能动弹，不能运转;塞入;塞进;挤进;挤满;（发射无线电波）干扰;即兴演奏。例句有：

1、The bus was delayed in a five-mile jam.

公共汽车因长达五英里的交通堵塞而延误。

2、Cut the cake in half horizontally and spread jam on one half.

把蛋糕横切成两半，把果酱涂在半面上。

3、There's a loose part that keeps jamming the mechanism.

有个零件松了经常卡住机器。

4、The company's lines have been jammed all day with people making complaints.

公司的电话整天都因人们打投诉电话而占线。

5、I can't get the door open ─ it's completely jammed.

我打不开门——卡死了。

6、Hundreds more people were waiting outside the jammed stadium.

还有数百人在拥挤不堪的体育场外等候。

7、There is a new device for cars that warns drivers of traffic jams ahead.

有一种新的汽车装置可提醒司机前面有交通堵塞。

8、She sat in the car, silently fuming at the traffic jam.

她坐在汽车里，心中对交通堵塞感到十分恼火。

9、Hundreds of fans jammed the switchboard for over an hour.

在一个多小时里，好几百个崇拜者打去电话，交换台应接不暇。

10、Have some of my plum jam ─ but mind out for the stones.

尝尝我的李子酱——但得当心有核儿。