Now that much of Europe is experiencing a heatwave many people need to
take refuge from the heat in the shade. In
English, When we talk about
being in the darker area where sunlight doesn't directly hit, we call
this 'the shade'. This is uncountable so you can't say 'a shade' in this
context. If you want to speak about a specific darker area outside
which doesn't directly catch sunlight, we call this 'a shadow', a
countable noun. For example we can say 'the shadow of the tree is very
big' or 'if I go into the sunlight, I will have a shadow'. So use
'shade' in a general sense and 'shadow' in a specific sense. Hope this
helps. http://www.clasesinglesonline.com