Tricky words are taught along side the letters and digraphs from phase 2 on wards . These words can't be sounded out for reading and writing, children need to just remember the spelling of these word. A lot of these words go on to be part of the Year 1 and 2 'Common Exception Words'.
Set 1 tricky words begin within phase 2 in reception and continue to be taught throughout the phases. Some children pick them up quickly and other find it a little trickier. Children can make good progress phonetically but the tricky words just don't click, they will you just need to support regular practise at home.
Some great tricky word (we also call these super power words) videos that we use in class are by Mr Mc, he does some FANTASTIC videos for super power words, the link below will take you to 23 of his videos! ENJOY!