词汇比较
commence vs start vs begin
I noticed the word commence when I recite GRE, the meaning is similar with the word start and begin. The Oxford dictionary explain the meaning as: to begin to happend; to begin sth. Chinese meaning as 开始发生，着手。 So I start to think about the difference, and which context can I use commence. So I dive into the example sentences.
The meeting is scheduled to commence at noon. Here commence used as intransitive verb. It means something starts.
I will be on leave during the week commencing 15 February. week commencing, week leave
使用场合
commence is used in a formal （正式）situation， start/begin is used more often in an informal situation.
According to the Merriam-Webster's Dictionary of Synonyms
Traditional usage often supports the choice of commence in reference to court proceedings, religious or other ceremonies, or industrial, commercial, or military operations" (p. 94)
reference
weary vs tired vs fatigued
weary
very tired, especially after you have been working hard or doing sth for a long time
be weary of doing sth
fatigued
very tired, both physically and mentally 身心交瘁；精疲力竭