ADV
大多;多半;主要地
You use mostly to indicate that a statement is generally true, for example true about the majority of a group of things or people, true most of the time, or true in most respects.
例句
I am working with mostly highly motivated people...
和我共事的人大多积极性极高。
Cars are mostly metal.
轿车的大部分部件是金属制造的。