'While' and 'as' are used to describe actions that occur at the same moment that something is in progress. 'While' and 'as' are sometimes confused with the preposition 'during'. Both express the same idea, however, the structures are different. 'While' and 'as' are time expressions and take a subject and verb. 'During' is a preposition and is used with a noun or noun phrase. Take a look at the following examples to note the difference.
“while”和“as”用來描述在同一時間正在進行的事。"While”和“as”有時會與介詞“during”混淆。兩者都表達了同樣的意思，然而，結(jié)構(gòu)卻不同。"While”和“as”是用來表達時間，有主語和謂語動詞。“During”是一個介詞，和名詞或名詞短語連用。看看下面的例子來分清差異。

Notice how the meaning remains the same in both structures:
注意在兩種結(jié)構(gòu)中，它們的含義如何保持相同：

Examples - During:
During的例句

We discussed the situation during lunch. (noun)
我們在午餐時討論了一下情況。（名詞）

They are going to visit the Empire State Building during their visit to New York (noun phrase).
他們將在訪問紐約期間參觀帝國大廈（名詞短語）。

The following sentences can also be expressed using the time expressions 'while' or 'as'. Be sure to take careful note of how the structure changes.
下面的句子也可以用表示時間的‘while’或‘a(chǎn)s’來表達。一定要注意它們結(jié)構(gòu)的變化。

Examples - When / As:
When/As的例子：

We discussed the situation while we were eating lunch. (full adverb time clause with subject and verb)
我們在吃午飯的時候討論了情況。（主謂齊全的時間狀語從句）

They are going to visit the Empire State Building as they visit New York. (full adverb time clause with subject and verb)
他們將在參觀紐約時參觀帝國大廈。（主謂齊全的時間狀語從句）

Future: Use 'while' or 'as' to state something that occurs at the same moment that something else - the main focus of the sentence - important will occur.
將來時態(tài)：使用“While”或“as”來表示某事和另一件事同時發(fā)生，另一件事重要的事即句子的焦點。

Time clause: present simple
時間從句：一般現(xiàn)在時

Main clause: future form
主句：一般將來時

Examples:
例子：

We're going to speak about the modifications as you eat lunch.
當(dāng)你吃午飯的時候，我們談?wù)勑薷牡膬?nèi)容。

She'll work out the order details while we discuss what to do next.
當(dāng)我們討論下一步該怎么做時，她會整理出訂單的細(xì)節(jié)。

Present: Use 'while' or 'as' to express what always happens when something else important takes place. This use of 'while' and 'as' is not as common as the time expression 'when'. Notice that the preposition 'during' is often used in place of 'while' or 'as' to express the same idea.
現(xiàn)在時：用“while”或“as”來表達當(dāng)其他重要事情發(fā)生時，一直發(fā)生的事情?！皐hile”和“as”的這種用法不像表達時間的“when”那么普遍。介詞“during”經(jīng)常用來代替“while”或“as”來表達相同的意思。

Time clause: present simple
時間從句：一般現(xiàn)在時

Main clause: present simple
主句：一般現(xiàn)在時

Examples:
例子：

He usually has lunch while he take a walk around the campus.
他經(jīng)常在校園里散步的時候吃午飯。

Angela often takes notes as the meeting progresses.
安吉拉經(jīng)常在會議進行的時候做筆記。

Past: 'While' and 'as' are used in the past to express an action that was occurring at the moment when something important happened. 'While' and 'as' are also used to express two actions that were happening at the same moment in the past.
一般過去時：“While”和“as”用在過去時中用來表示當(dāng)重要的事情發(fā)生時，正在發(fā)生的動作。“While”和“as”也用來表示過去發(fā)生在同一時刻的兩種行為。

Time clause: past simple OR past continuous
時間從句：一般過去時或過去進行時

Main clause: past simple OR past continuous
主句：一般過去時或過去進行時

Examples:
例句：

Doug was drying the dishes while we were watching TV.
我們在看電視的時候，道格正在烘干盤子。

Peter took notes as we discussed the merger.
彼得在我們討論合并的時候做了筆記。

As Long As / So Long As = During an Entire Period of Time

'As long as', and 'so long as' are similar in use to 'while' and 'as'. However, 'as / so long as' is used for longer period of times, while 'when' and 'as' are used for more specific, shorter periods of time. 'As / so long as' are also used to stress that something will happen, happens or happened over the entire period of time in an emphatic manner. Although examples are provided for ?the past, present and future, 'as long as' and 'so long as' are generally used with future forms. Notice the use of tenses:
“As long as”和“so long as”的用法類似于“while”和“as”。然而，“as/so long as”用于更長的時間，而“when”和“as”用于更具體、更短的時間?！癮s / so long as”也用來加強語氣表達過去發(fā)生，正在發(fā)生或?qū)⒁l(fā)生的事。雖然提供了過去、現(xiàn)在和未來的例句，但“as long as”和“so long as”通常用于將來形式。注意時態(tài)的用法：

Future: Use 'so / as long as' that something will not happen for the entire period of time expressed by the time clause with 'as / so long as'.
將來時態(tài)：使用“so/as long as”來表達在這段時間內(nèi)（不）會發(fā)生的事。

Time clause: present simple
時間從句：一般現(xiàn)在時

Main clause: future form
主句：將來形式

Examples:
例句：

I will never play golf as long as I live.
只要我活著，我就永遠不打高爾夫球。

She will never return so long as she goes out.
只要她走了，她就不會再回頭。

Present: Use 'as / so long as' to express that something happens or doesn't happen over the entire period of time that another event occurs.
現(xiàn)在時態(tài)：使用“as/so long as”來表示在另一個事件發(fā)生的整個時間段內(nèi)某事發(fā)生了或不會發(fā)生。

Time clause: present simple
時間從句：一般現(xiàn)在時

Main clause: present simple
主句：一般現(xiàn)在時

Examples:
例句：

As long as he plays the piano, I go for a walk.
只要他彈鋼琴，我就去散步。

She visits him every month, so long as her husband has to take care of business in town.
只要她丈夫在鎮(zhèn)上做生意，她就每個月去看他一次。

Past: Use 'as / so long as' to describe an action that did or didn't occur over a longer period of time in the past.
過去時態(tài)：用“as/so long as”來描述過去或更長時間內(nèi)做過或沒有發(fā)生過的行為。

Time clause: past simple
時間從句：一般過去時

Main clause: past simple OR past continuous
主句：一般過去時或過去進行時

Examples:
例句：

She didn't get any exercise as long as she was working 60 hours a week.
只要她每周工作60小時，她就沒有運動。

Peter didn't enjoy his work so long as he was in the house.
只要他在家里，彼得就沒法開心地工作。