Prefixes and suffixes change the meaning of roots, therefore to properly analyze a word it is often helpful to know what is the prefix and what is the root. Prefixes are a syllable or syllables in front of a word, but is there a definitive rule/ method to determine where one syllable (the syllable last of the prefix) starts and ends.
example: a- is a prefix meaning to, towards, or in the process of, as in aglow and aside. Apple also starts with a-, but does not have an a- prefix and the double consonant distinguishes the syllables. Another word: abyss would be harder to distinguish in this way: a-byss or ab-yss. Another example: alula: a-lu-la or al-u-la
Is there a rule (or set of rules) to generalize the distinguishing of prefixes from roots: it could contain the double consonant rule, but needs more to work most of the time except with irregulars/ exceptions. If able, the rules should account for multiple syllable prefixes like contra-. If needed, the rules can rely on a set of known prefixes.