begin 最常用词，含义广泛，其反义词是end，多用于行动、工作等的开始。
start 在许多场合可与begin通用，但start侧重动作的起点。
commence 可与begin换用，但commence系书面正式用词，语气庄重，特指有正式程序或一定仪式，或某种正式行动的“开始”。
initiate 指创始或发起，侧重某过程的第一步，不考虑结束，强调起始。
inaugurate 指正式而隆重的开始。
参考例句
1. Each side announced in advance that they expect the other to initiate movement. 双方都事先宣布说，他们希望另一方主动提出行动方案。
2. They need to be open to new ideas and willing to initiate within their organization. 他们需要对新思想敞开大门，并愿意将其引进他们组织。
3. In grade of Heliodromus (sun runner) under sun, the initiate imitates Sun at the ritual banquet. 在太阳之下的太阳信使等级，在典礼的宴会上开始模仿太阳。
英英解释
n.
1. someone new to a field or activity
2. someone who has been admitted to membership in a scholarly field
3. people who have been introduced to the mysteries of some field or activity v.
1. bring into being
2. take the lead or initiative in; participate in the development of
3. accept young people into society, usually with some rite
4. bring up a topic for discussion
5. prepare the way for
