When a Norman-French word was adapted into English, the loanword usually appears different than the modern French word in spelling and/or pronunciation. There are mainly two reasons for this. First of all is the developments that both languages have suffered. The second and most important reason is that the language the Normans spoke was very differet to that spoken in Paris. Words like carry and cauldron corresponded to the Central French words charrier and chaudron. Sounds like w were not much seen in Central French, but they were in Anglo-Norman, maybe due to the proximity to Flemish and Dutch. Thus, words like wicket, correspond to the Central French guichet.

Regarding pronunciation, vowels also behaved differently in the two languages. In Old French the dipthong ui was accented on the first element. In Anglo-Norman the i dissappeared, leaving just the u [y]. In ME it became either u or iu. That is the explanation of how the word fruit for example (same graphical representation in both MdE and MdF) is pronounced differently in English and French.