We say:

puH Duj 

muD Duj 

bIQ Duj 

However, we say:

veSDuj 

may'Duj 

toQDuj

tlharghDuj 

lupDujHom

And there is the {paq Duj} too, which since we don't have any of those in greece, I don't know what it is, nor do I care to find out either..

Now, from the examples above ({paq Duj}, whatever the ghe''or it is, aside), it shows that seemingly/apparently in Ca'Non, when a ship is described on the basis of *where* it travels, the two words are written separately, but when a ship is specified on the basis of its' mission, then the two words are smooshed together..

So, the question arises:

If we want to say "love ship" (as ridiculous as it may sound), do we need to write {parmaqqay Duj} or {parmaqqayDuj} ? Or if we need to say "food ship", do we write {Soj Duj} or {SojDuj} ?

Or is it, that only god (i.e. maltz), has the right to be smooshing words together ?

Words get smooshed together when the population using the words comes to see them as a single word. In English, compound words often go through the following stages: they start as two words used together to mean something, then they become hyphenated, then the hyphen is removed and they're one word. An example: child care started as two words, later it was hyphenated to child-care, until finally today it is commonly found as one word, childcare. We started with electronic mail, which soon became e-mail, and now the hyphen is rapidly disappearing in dictionaries, to become email.

The single words that end with Duj probably have their origin in this. Modern Klingons appear to be more interested in spaceships than other types of vehicles, such that Duj is generally thought of as a spaceship by default, without comment. So they make terms that combine with this default meaning, and the terms are common enough to be turned into single words. But when you talk about non-spaceship vehicles, these aren't going to be so common as to become single words.

We can't create single-word compounds ourselves, because we don't have access to Klingon culture to determine which words THEY have decided are common enough to be single words. But love ship is obviously parmaq Duj, and food ship is obviously Soj Duj, because neither is likely going to be a thing for Klingons. But without guessing, we have to assume these to be the case because we can't assume we'd know which words Klingons would jam together, any more than we can predict which words are going to be jammed together in English in the future.

-- 
SuStel
http://trimboli.name