Agglutination. Compound words can be tricky. I recall a language (or maybe just a hypothetical example) which referred to some small fruit, not a grape, as a purple-berry... a grape was a wine-berry (like Esperanto's vinbero (though purpurbero has no specific meaning in Esperanto)). Upon first sight wine-berry would be easily recognizable by a member of a culture that does wine of the grapish sort, but not by a person who doesn't know wine or is accustomed to some other recipe. Either way, a purple-berry could easily be mistaken for any purple berry.
The Glosa word for neighbor is para-pe, or para-fe or para-an if you want to be more specific. Beside-person? Beside what, and in what sense? To me, that sounds more like a co-worker or spouse, or the passenger next to me in a plane, if taken more literally.
Sometimes that's not a big problem, because once you learn that a purple-berry is your blackberry, and a wine-berry is your grape, you'll be okay. (Blackberry? Uh-oh. Yep, English has its problems too!) And once you've embraced the word, it can help you remember the component words. Speedwords' zofid for dog helps me remember zo (animal) and fid (faithful, loyal). But maybe that's a cultural thing, too. Are dogs considered faithful everywhere?
If the breaking down of a compound word into its components doesn't point directly at its meaning, if you have to learn the combinations as discrete entities, then 1) you've lost some of the utility of agglutination and 2) you might just as well have a separate word for the thing.
Makes me wonder if agglutination-type wordbuilding really works well between cultures that don't already have a lot in common. In the early stages anyway. Once you're familiar with it, any language can work. The question is, how long will it take to reach that point? And that's an important question for an International Auxiliary Language.