Final answer:
The 'FFF' in compositions refers to the correct spelling of the sound /f/. Usually, it is spelled as 'f', but in some cases, it can be spelled as 'ff' due to assimilation or specific patterns. It can also be spelled as 'ph' or 'gh' in certain words.
Step-by-step explanation:
The FFF in compositions refers to the correct spelling of the sound /f/. Usually, the sound /f/ is spelled as f at the beginning and end of words. However, in some cases, it is spelled as ff due to assimilation, the VCC pattern, or when it is between a short vowel and 'le'. For example, words like fluff, stiff, and staff use the ff spelling due to the VCC pattern at the end of the word. The only cases of ff spelling due to twinning are in iffy, iffier, and iffiest.
It's worth noting that the sound /f/ can also be spelled as ph in words like phone or gh in words like enough or tough. Additionally, the sound /v/ is typically spelled as v, except in the word 'of' where it is spelled as f.