As and while denote when... What a difference the times make

1. The as clause also indicates that one thing is happening and another thing is also in progress. But unlike the while clause, the as clause uses a shout that does not use the continuous tense, but only the simple past tense. As clause can generally be translated as "edge".

For example: as my mother sang those old songs, tears ran down her cheeksTears ran down my mother's cheeks as she sang those old songs.

the students took notes as they listened.The students took notes while listening to the lecture.

2. When the event expressed by as is often only the background or condition for the action of the main clause to occur, as is only a secondary time explanation, unlike the while clause that emphasizes the meaning of the while action itself. Therefore, as is often translated as "with". For example:

as the time went on，theweather got worse.As time went on, the climate got worse.

the atmosphere gets thinner and thinner as the height increases.As the altitude increases, the atmosphere becomes thinner and thinner.

3. In a few cases, if the emphasis action is happening, the as clause can also be used in the ongoing tense.

the sad mother sat on the roadside, shouting as she was crying.The sad mother sat on the side of the road, crying and screaming.

as we were going out, it began to snow.Just as we were heading out, the snow started to fall.

As means "just......(just as, at the same moment that)" "With the ......(while, when)" can represent either a specific point in time or a period of time. While means "in......At the same time (at the same time that)" "" in ......Period (for as long as, during the time that). From the point of view of the meaning of the word while, it can only represent a period of time, not a specific point in time.

When means "to ......."at the time that" and "whenever" ......Just ......(as soon as)" in ......After (after)". The concept of time represented by it is broader, and the as or while in the above example sentences can be replaced by when, because when can not only represent the point in time with the split, but also represent a period of time. In time, it can represent both "point coincidence", "line line coincidence", and "point line coincidence".

For example: 1. When he came in, she went outHe came in, she went out. (dots coincide).

The action of the when clause in this sentence represents a point in time, and when can be replaced by as, but not while.

2、when he came back，i was doing some washing.When he came back, I was doing the laundry. (dots and lines coincide).

The action of the when clause in this sentence represents a point in time, so it can only be replaced by as, not while. 3. when mary was writing a letter, the children were playing outside.

While Mary was writing the letter, the children were playing outside. (Lines Coincident).

The action of the when clause in this sentence indicates a period of time, so it can be replaced by as or while.