The fish is delicious. It melts in your mouth.
The ice is melting under the sun.
Why do we use present simple in the first sentence and present continuous in the second one, with the same verb, to express an action in progress at the moment of speaking?
You come up with such interesting queries!
In the first sentence, you are stating a fact about the fish and how tender (as opposed to 'chewy') it is. The intention of your comment is NOT to suggest, "look everybody, have a look and see how it is melting in my mouth without my really having to chew it. Quick before the melting is finished and you can't see it happen any more." - the latter would be the temporary nature of the ongoing action/event, and with a definite end, that is conveyed with Present Continuous!
With the second sentence - that is Present Continuous -there is an ongoing action/event, with a start prior to NOW, perceived as temporary, and that a definite end to the action can also be perceived by the speaker.
Last edited by David L.; 10-Mar-2009 at 10:39.