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. The story begins with their marriage. 故事以他们的婚姻开始。
2. Does your spring term begin in May ? 春天学期是在五月开始的吗？
3. The general signaled to his officers for the attack to begin. 这位将军向他的军官们发出开始攻击的信号。
英英解释
n.
1. Israeli statesman (born in Russia) who (as prime minister of Israel) negotiated a peace treaty with
2. take the first step or steps in carrying out an action
3. have a beginning, in a temporal, spatial, or evaluative sense
4. set in motion, cause to start
5. begin to speak or say
6. be the first item or point, constitute the beginning or start, come first in a series
7. have a beginning, of a temporal event
8. have a beginning characterized in some specified way
9. begin an event that is implied and limited by the nature or inherent function of the direct object
10. achieve or accomplish in the least degree, usually used in the negative
11. begin to speak, understand, read, and write a language
