1. 用作名詞，是集合名詞。作主語時，謂語用單數(視為整體)或復數(考慮其個體成員)均可。如：

The crowd moves on, and no one tries to stop it. 人群向前移動，誰也沒試圖阻止。

The crowd were running in all directions. 人群往四面八方跑去。

強調人數多時，可用復數形式。如：

There were crowds of people waiting to get in. 有許許多多的人在等著進去。

2. 用作動詞，表示“聚集”、“擠滿”，可用作及物或不及物動詞。如：

Shoppers crowded the streets. 買東西的人擠滿了大街。

He managed to crowd into the train. 他總算擠上了火車。

People crowded round to get a better view. 人們爭相圍觀。

常用結構 be crowded with。如：

The hall was crowded with people. 大廳擠滿了人。

The exhibition was crowded with visitors. 展覽會擠滿了參觀的人。

3. 派生形容詞 crowded 意為“擁擠的”。如：

crowded trains (hotels, roads, shops) 擁擠的火車(旅館，道路，商店)

但是，漢語的“擁擠的交通”不能直譯為 crowded traffice, 而是用 busy [heavy] traffic。