I. What is the 是 ... 的construction and when is it used?

I. What is the 是 ... 的 construction and when is it used?

The 'shì 是 ... de 的 ' construction refers to a grammatical structure which focuses on when, where or how an action took place. It is used to seek or provide information about the time, place, manner, agent, or target of the action. For example, if the fact is that Xiǎomíng went to Beijing, and the information to be sought is when, with whom and by what means of transportation that he went to Beijing, the questions and answers would be:

Questions Seeking Information	Questions Seeking Clarification
When did Xiaoming go to Beijing? Xiǎomíng shì shénme shíhou qù Běijīng de? 小明是什么时候去北京的？	Did Xiaoming go to Beijing yesterday? (last year? etc.) Xiǎomíng shì zuótiān qù Běijīng de ma? 小明是昨天去北京的吗？
With whom did Xiaoming go to Beijing? Xiǎomíng shì gēn shéi qù Běijīng de? 小明是跟谁去北京的？	Did Xiaoming go to Beijing alone? (with his mom? etc.) Xiǎomíng shì yí gè rén qù Běijīng de ma? 小明是一个人去北京的吗？
How did Xiaoming go to Beijing? Xiǎomíng shì zěnme qù Běijīng de? 小明是怎么去北京的？	Did Xiaoming fly to Beijing? (go by bus? /train? etc.) Xiǎomíng shì zuò fēijī qù Běijīng de ma? 小明是坐飞机去北京的吗？

The answers to these questions would be:

Answers
He went to Beijing yesterday. Tā shì zuótiān qù Běijīng de. 他是昨天去北京的。
He went to Beijing with his father. Tā shì gēn tā fùqin qù Běijīng de. 他是跟他父亲去北京的。
He drove to Beijing. Tā shì kāi chē qù Běijīng de. 他是开车去北京的。

The 'shì 是 ... de 的 ' construction does not deal with the completion, duration and frequency of an action or the quantity of the object. It focuses on the circumstances around the fact, not on the fact itself.