These 4 weeks introduce some new GPCs in the same way as in previous phases. Five of these GPCs are known as split digraphs. They are a_e, e_e, i_e, o_e, u_e. These used to be taught as magic e but now it is recommended that children learn to recognise these in the same way as other graphemes but simply explaining that in these particular graphemes the two letters work as a team but they aren't directly next to each other.
These 3 weeks introduce the idea that some graphemes can be pronounced in more than one way. E.g. the ch grapheme can be pronounced in each of these ways check, chef and school. This is a vital lesson for children to learn and they need to learn to apply it in their reading. Make sure you model trying to read a word by sounding out the most obvious phonemes then blending it together. If it doesn't make sense model looking at each grapheme and seeing whether there are alternative pronunciations. Try sounding out the word with the alternative pronunciation and blending it together. Does it make sense now? This can be quite a jump for some children to make as they have to realise that English isn't quite as straightforward as it once seemed. However, it can also be quite empowering to know that just because a word doesn't make sense first time, it doesn't mean that they can't go back and figure it out for themselves.
This part of Phase 5 is all about learning that some phonemes have more than one spelling (in fact some of the really awkward ones have loads of different spellings). In the past, some people have thrown in the towel with phonics at this point and decided that there is no point in teaching it as there is no rhyme and reason to how these phonemes are spelled. The fact is that there is much more rhyme and reason to which spelling we use for these phonemes then most people are aware of. Certainly we can teach children how to make the best guesses when spelling these phonemes. They aren't always infallible but it leaves children with far fewer 'tricky' spellings that they have to just learn in other ways. It is important that children try to discover these rules by themselves by playing investigative type games and looking for patterns.