Following on from yesterday’s post on Hebrew syllables…
The way syllables work in Aramaic is mostly the same as in Hebrew. The most significant difference is that long vowels (אָ אִי אֵי אוֹ אוּ) can occur in closed, unaccented syllables.
To use Reymond’s example, it means that with words such as הוֹדְעָךְ it is difficult to tell if the first syllable is open or closed. In Hebrew it would be an open syllable (הוּ דְ עָךְ) since long vowels don’t occur in closed unaccented syllables. However, in Aramaic there are two options. It could be open (as in Hebrew) or closed (הוּדְ עָךְ).
Apparently, it is difficult to tell which is the case, and so the general rule of thumb is to assume that the syllable is open unless you know otherwise (i.e. follow the Hebrew rule).