英文問題---有句野吾知用緊咩tense

這句子用了是假設法過去完成式，用來表達與過去事實相反的想像，或過去沒有實現的希望，這種句子的組成如下：

從屬子句用過去完成式動詞，主要子句用would(should, could, might等）＋have+過去分詞，如：

If I had known it, I should have told it to you.
If I had had money enough, I could have bought the house.

你的句子用was to取替would，是有更肯定的意思，如：be to do something比will do something更肯定，更早有安排好之意

continuous 是沒有間斷，但continual也可指多次重複（當中不是連續不斷），而straight卻是副詞，而不是形容詞

希望幫到你！

The first place uses simple past tense. 'to have been used' is not a part of the main verb, but rather a usage of to-infinitive. it describes a state.
The second place uses past perfect tense. This tense is usually used with simple past tense to indicate chronological order of events.

Grammar,The conditional mood of a verb eg had been in There had been a storm.
If there had not been a storm,the office was to have been used!(present perfect passive tense)
Continuous adj= another term for Progressive sense,together.eg The graph is a smooth unbroken curve in functunal Maths.
Continual adj, constantly or frequently occuring

2012-01-02 18:50:32 補充：
past prerfect and perfect conditional have had a sense here.

The new office is to be used next month. (said two months ago)

be [+ to infinitive] = used to show that something will happen in the future (Cambridge dictionary)

Because of a storm (thereafter), the new office cannot be used as scheduled.

We can use the third conditional to describe the situation. The conditional type 3 is a structure used for talking about unreal situations in the past. In other words, it is used to talk about things which did not happen in the past.
Type 3: if + past perfect + perfect conditional The new office would have been used last month if there had not been a storm. 本來上個月已使用

The new office was to be used last month, but it is now still half-finish because of a storm. 原本計劃上個月使用


2012-01-02 19:09:21 補充：
continuous is a synonym of continual (both adjective)
"straight" is an adverb when it means "continuously without interruption"
e.g. They had been working for 16 hours straight.