Final answer:
The most common spelling of /a/ at the end of a syllable is the letter , which can represent the short sound in words with at the end of a syllable, like in 'ball'.
Step-by-step explanation:
The spelling of /a/ most common at the end of a syllable is typically , which can spell a short sound in certain words. When considering the double at the end of a free stem, an right in front of it will make the short sound, as in the word 'ball' (pronounced [bɔl]). However, when the double is located in the middle of a stem, the letter before it will spell the standard short sound as in 'ballot' ([bálət]).