•The chocolate is being melted by the sun. How should I mean the connotation of that phrase?
Instead of "The chocolate was melted by the sun".

Question

•The chocolate is being melted by the sun.   How should I mean the connotation of that phrase?
Instead of "The chocolate was melted by the sun".

Answer

'Was melted' suggests that the process is over.

'Is being melted' means that this is happening at the moment, and that the chocolate is currently part-way between solid and liquid.