问题：Would you mind offering some advice about how to organize a motivation letter (500 words required)? Which one should I focus on, my understanding of the subject, interest about the program, my internship, my competitions and awards or something else? Looking for your advice, thanks a lot!

回答：

A motivation letter is precisely what the name implies: What is your specific motivation for the school, the program, and the discipline you will pursue there.

“Which one should I focus on…?” I’m not sure you should be aiming to focus exclusively on any of those facets of your application that you’ve listed:

[1] Presumably “understanding of the subject” and “interest about the program” are highly interrelated?
[2] Your internships, my competitions, awards, and anything else (life experiences, qualifications, work, personal qualities) that has been NOTABLE, ENRICHING, and RECENT is/ are means to SUBSTANTIATE your interest in the program/ understanding of the subject.

The items noted at 

[1] are the CLAIMS of your motivation letter; the items noted at 
[2] are the EVIDENCE that will support those claims.

Know what you’re going to DO with the letter in advance (i.e. list out briefly, 5-10 points that summarize the items at [1] above). 

Begin with a short introductory paragraph in which you use the typical pleasantries of a letter to lead into the substantial aspects of the letter smoothly. The paragraphs you write should be composed of EVIDENCE (identified above) that supports the CLAIMS (also identified above). You should group relevant material logically and draft so the paragraphs flow together smoothly.

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