Its primary meaning is “at the same time as”. (While mother read the letter aloud, the family listened in silence.) Most language critics recommend that the word be restricted to this use, linking two simultaneous events.

Still, there is widespread, if sometimes grudging, acceptance of “while” used to represent a contract without any reference to time, in the sense of either “although” or “whereas”:

While everyone was astonished by the news, no one said a word until she had finished. (while=although)

Not all the listeners had the same reaction. The children were delighted at the prospect of meeting their Taiwan cousins at last, while Grandfather maintained a frosty reserve. (while=whereas=but, by contrast)

Unlike all the words we have considered so far, “with” is a preposition. But it is so often used as a logical connective – and so often in a vague or confusing manner – that it is worth considering alongside the conjunctions, adverbs and adverbial phrases that usually serve the ideas together. [with，虽然是个介词，但也经常用作逻辑联结词，语义通常模糊不清]

The difficulty arises when “with” is used in such as vague sense that it gives no precise indication of the relation between the two elements it joins.

Example:

A: With professional familiar with the country’s laws and proficient at foreign languages, there offices will save the time and energy of foreign trademark registrants.[这里的“with”意义模糊，无法明确表达两个句子之间的关系，professionals可以be familiar “with” the laws，但offices无法通过“with”与professionals建立联系]