In other articles in this series, we have seen how the verb system in English is one of the biggest problems for non-native learners. In most cases the difficulties are in choosing which tense is the right one to express a particular idea; for example, whether to use the past simple or present perfect. Sometimes, however, the difficulty is in the actual formation of the verb string, particularly when the string consists of auxiliaries and participles and a modal verb. Here are some examples in order of increasing complexity:
In such complicated sentences, the difficulty is not necessarily in choosing which tense to use but in actually collecting together the necessary parts and putting them in the correct order.
As a frivolous example, consider the following sentence:
The road would have had to have been being built.
It is grammatically possible, although fortunately it's rare that we need to express such a complex thought. However, it does give an example of the kind of complexities that the English verb system hides for the learner.
Can you think of a situation in which you might meet this sentence?
If I had wanted to see how the construction workers actually made the road, the road would have had to have been being built - (but the road wasn't being built and so I didn't get to see how it was made).