The noun-noun construction

The noun-noun construction explains the usage of multiple – usually two – nouns in a row. When two nouns follow each other, it usually creates a genitive construction. For instance Noun1 Noun2 is translated as "the Noun2 of Noun1" or "Noun1's Noun2". (1)

For two nouns stuck together with no space and forming a new word (e.g. veQDuj), see ➞ compound noun.

Basics

There are two ways to interpret the noun-noun construction: genitive or possessive. Possessive is a subset of genitive.(2)

Possessive means the first noun owns, or holds, or is otherwise associated with the second noun.

• HoD quS = captain's chair; chair of the captain; chair owned by, held by, or otherwise associated with the captain.

Genitive means the first noun modifies the meaning of the second noun, typically by narrowing the possible types of noun you're talking about.

• baS 'In metal drum: you're not saying metal owns, holds, or is associated with the drum; you're narrowing down what kind of drum you mean by saying it's the metal kind.

Possessive is a subset of genitive because a possessive noun also narrows the possible meanings of the second noun. Of all possible chairs, the one you're referring to is the one owned, held, or associated with the captain.

'aqroS qughDo maximum cruising speed is an example of a genitive construction that is not a possessive construction. The cruising speed doesn't own, hold, or find itself associated with the concept of maximum. Instead, you're specifying what kind of cruising speed you're talking about by narrowing it down to maximum cruising speed.

English sentences do not make this distinction clear, and Klingon almost doesn't distinguish at all between them. I can think of one instance where it does: when using pronouns with "relative area" nouns, you don't use the possessive suffixes; you use pronouns in a noun-noun construction:

• jIH Dung area above me instead of DungwIj;
• maH 'em area in front of us instead of 'emmaj.

Otherwise, it's unclear whether, for instance, tlhIngan Hol means "language associated with Klingons" or 2language specified by its Klingonness". Or if you don't know the context, one might have a bunch of chairs lined up, and you're asked which one is the chair some hypothetical captain might use. There the phrase HoD quS wouldn't be possessive, because you're not talking about a captain owning or holding or being associated with the chair; you're talking about narrowing down the type of chair.

'aqroS qughDo talks about a cruising speed: "maximum cruising speed", instead of "half cruising speed" or "minimum cruising speed".
qughDo 'aqroS talks about a maximum: "cruising speed maximum", instead of "emergency speed maximum" or "thruster speed maximum".

Rules

• Any kind of noun can be used for both slots
• One can have as many nouns as needed
• Used nouns can have suffixes
• Only the second noun should/can have a syntactic marker

Examples

mogh puqloD	son of mogh, mogh's son	➞ naming your house
tlhIngan Hol	language of the Klingons
qul tuq	The House of Fire	Name of a Klingon opera
lojmIt 'em	behind the door, the door's area behind
SoH 'em	behind you, the you's area behind	pronouns can only be used with area descriptions(3)
Duj meHDaq	on the bridge of the ship
Dujvam pong	the name of this ship, this ship's name
Duj HoD pong	the name of this ship's captain
DujHomvam HoDqoq pongna'	the true name of this little ship's so called captain

Is it a genitive or not?

This question pops up very often and confuses beginners and advanced. The answer is quite cler and easy:

The Klingon noun-noun construction is always genitive. When one noun modifies the meaning of another noun, that's genitive. That's true whether you translate it "noun 2 of noun 1" or "noun 1's noun 2" or "noun 2 made of noun 1." What's important is that noun 1 is modifying the meaning of noun 2. That's what makes it a genitive relationship.

vIghro' ghu is a noun-noun construction, which means they're in a genitive relationship. It's a ghu. What kind of ghu? A vIghro' kind of ghu. It's a Hol. What kind of Hol? A tlhIngan kind of Hol. It's a pegh. What kind of pegh? A nuH kind of pegh. And so on.

Exceptions

• The slang expression wIj jup my friend violates two rules: a) the words are translated in the incorrect order being a literal translation for "my + friend", and b) the possessive suffixe should be the one used for beings capable of language = -wI'.
• Although not commonly accepted as a mistake, Marc Okrand has used the suffix -Daq incorrectly on two examples. See details in ➞ Canonical Exceptions.

The space in between

When two nouns are combined without a space between them, they are technically creating new word, called a compound noun.
➞ see main article on spacing

References

1 : The Klingon Dictionary, chapter 3.4

2 : Message to the mailing list "Re: [tlhIngan Hol] The use of 'aqroS" by David Trimboli, Wed Aug 2 20:13:50 2017

3 : Klingon for the Galactic Traveler