由 (yóu) is used to emphasize who is the doer or initiator of an
action, a bit like in English where we might say: "Andy ''is the
one who...."
Structure
Topic + 由 + Person + Verb
Examples
- 这 件 事 由 我 负责。I am responsible for
this.
- 这 是 由 他 决定 的，你 就别 干涉 了。This is for
him to decide, don't meddle.
- 太 悲剧 了，会议 由 王总 主持，肯定 会 很 无聊！Oh no.
This meeting is being led by the head manager. It's definitely
going to be boring.
Note that 由 not a passive marker.
See also
Sources and further
reading
Books
Category:
B2 grammar points