Reading ? example :
Crabs and lobsters have shells which are a sort of hard skin. A lobster has a shell. It flaps its tail to swim. As the lobster gets bigger, its shell splits. The fresh shell is soft to begin with, but it soon hardens. There are lots of different sorts of crabs. Some are good at swimming and some have long thin legs.
-- Children should be able read this text comfortably and, after reading, say what it is about without looking at it.
-- They should be able to try to explain one or more of the words in bold and should be able to describe crabs (good at swimming / long thin legs).
-- They should then be able to talk about shells for a few minutes in correct English.