@javaprogrammer it most certainly does add up if your have an understanding of phonics and teaching English.
To cut a long story short:
*Reception autumn term = single letter sounds, double consonants (eg ll, zz, ff) and ch/sh/th/ck.
*Reception Spring term = vowel digraphs (eg ai, oo, oi)
*Reception summer term = consolidation of everything taught, longer words and suffixes (eg. -ed, ing)
This then allows the children to be able to write almost any word phonetically eg coat and then boan (instead of bone as this is an alternative spelling of the oa sound) and rain and then plai (because they haven't yet learnt -ay making the /ai/ sound)
*When they get to Year 1, the alternative sounds are taught and it is definitely trickier to get to grips with the different ways to write a sound eg /ai/ can also be written /a-e/ (cake) /ay/ (day) /ea/ (steak) /eigh/ (eight) /ey/ (prey).
Year 2 then moves over to teaching more spelling rules than explicit phonics.
From Reception the children are also taught the high frequency/tricky words (words that just need to be learnt because they are phonetic) such as 'what' 'was' 'she' 'has'.
All this steady structured approach enables children to learn to read and write independently. Most children will be able to ready longer books from the middle of Year 1. My son is currently in Y1 and reading Turquoise level books which is slightly above age expectations. So, by Y2 it is very possible that some children will be on free readers - not all children because as we know children are unique and learn at different rate - but the majority should be independent readers by Y2.
Sorry for the long reply!! 😝