A student asked me: Can I say 'I have been stopping this project / I have been starting this project' to express repeated action (with present perf. prog)? My answer was 'no', but I am having a hard time explaining why. The student is in an ESL class. Can I explain this without using complicated semantics?
I'm starting my homework = I haven't opened my books yet but presumably I will begin shortly or some time in the very near future.
I've started doing my homework = The focus is on the action and its results felt in the present (I am sitting at my desk, the books are open, etc.) If a time reference is mentioned then the Past Simple is needed e.g. I started doing my homework ten minutes ago
I've been doing my homework for over two hours = The Present Perfect Continuous is used for an action that began in the past and is currently in progress, i.e. doing. I am no longer in the process of starting homework, I am smack-bang in the middle of doing it.
They're stopping production = production will about to cease any moment, presumably it will happen soon.
They've stopped production = our attention is drawn to the fact that production has completely ceased. When the production stopped is not specified.
They have stopped producing X = The action which was stopped in the past and continues to the present is produce.
In order to use the PPC with stop, its meaning must be similar to "prevent from proceeding"
- The drug has only been stopping the seizures for a year
to halt somewhere for a brief visit or stay
- He's been stopping at all the best hotels
when it means to make a brief visit (to stop by) on one's way
People have been stopping by all day to pay their respects to Mrs. Bush.
and when the action of halting something or someone is repeated over a relatively limited span of time.
Police have been stopping and speaking to people all day in their bid to trace a missing woman.
I'm not sure about avoiding complicated semantics; it's either in many words or with words loaded with technical meaning.
To oversimplify considerably without using technical terms like aspect, perfect, or continuous, any verb form ending in '-ing' is talking about something that happens over a span of time (technically it is a grammatical 'continuous' aspect). But 'stop' and 'start' themselves are necessarily points in time (grammatically, this is the perfect or completed aspect).
To say "I have been stopping this project" is therefore very confusing, because either you stopped and are done, or you kept going and haven't stopped. To force some sense on to it would be like you are attempting to stop many times and failed to stop only to try stopping again, over and over.
"I am stopping now" is OK because you are in the process of slowing down to nothing, which takes a little bit of time. Also, you just tend not to say things like "I stop". While it fits all the grammatical patterns that people are taught, people hardly use it. Similarly, "I am stopping at" or "I am stopping by" more than one place is OK because you're doing a completed act at more than one place.
So it is strange (and not recommended) to say "I have been stopping a project" unless you really mean that you have stopped and started it many times including up to now.