[ztravis]

> Not all the time. And if they do, there still are subtle variations in suffixes.

There are many patterns and forms in the broken plurals themselves which you can pick up on and learn so that you often can correctly predict new ones without memorization. For example, you give:

-liss => lusuus

And likewise, most doubled nouns of this form take the same plural:

-jadd => juduud

-hass => husuus

-hamm => humuum

Still... this is far from a hard and fast rule, and it also takes a lot of time to build familiarity and notice these patterns. It's also something that al-Kitaab (for example) doesn't ever mention.

(just explaining... not implying that you aren't aware of this)