Tip: Watch out for strange ideas about the present perfect continuous and ‘going to’.
I usually do a ‘verb tense review’ mid-way through a course. When I elicit the uses of different tenses there are two things that students very often call out as facts they have learned. I have no idea where they come from, but they are both wrong.
The first is the difference between the present perfect simple and continuous. Students often say: ‘Oh yes, the pp continuous is when the action continues into the future’. No it isn’t! In the phrase ‘it has been raining all morning’ we have no idea whether the rain is going to continue or not – it depends entirely on the context. If you live in Manchester the answer is probably that it will continue, but that’s another story.
The real difference is that the pp simple looks back from the present to our life experience up to now, or gives the present result of a past action, whereas the pp continuous looks back from the present to an action in progress up to now. A good example for students is:
I’ve written the report. It’s on your desk.
I’ve been writing the report all morning. I’m exhausted.
In the first example our attention is clearly on the present result (the finished report on the desk) of the past action (the writing). In the second example our attention is clearly on the action in progress up to now. We’re not interested in the report, but in the activity of writing it.
And by the way … there’s almost no difference between pp simple and continuous with ‘work’ and ‘live’. Greater minds than mine will have to explain why, but there isn’t.
The second thing that I often hear from students is that ‘going to’ is for a near future, while ‘will’ is for a more distant future. Mmm. What about this: The world is going to end in around 4 billion years from now. You can’t get more distant than that. Here we’re talking about the ‘prediction’ uses of ‘going to’ and ‘will’, not other uses, and in this use either form is usually possible, including the example above. The situations where ‘going to’ is strongly favoured are where there is evidence now, in front of our eyes. The classic example is: ‘Look at those clouds, I think it’s going to rain’. (Back to Manchester again).
In class I push a pen ever closer to the edge of the desk, millimetre by millimetre, and ask students to warn me with a sentence that begins ‘Be careful!’. They invariably call out: ‘Be careful! It’s going to fall!’. It’s almost impossible to use ‘will’ here and it shows the ‘present evidence’ situation very nicely. Returning to the end of the world example, ‘going to’ is fine because scientists have evidence now. Again a good example for students because the word ‘evidence’ is used literally for the scientists.