Common language education focuses very strongly on Common's rather structured syntax and the proper way to form complete, grammatical sentences. Common linguistics, however, pays an unusually high degree of attention to the idea of 'proper' versus 'defective' statements. The former are the aforementioned properly structured sentences, and the latter are utterances that are missing some key element of licit structure. Defective statements are hugely important to idiomatic Common, and a grasp of this area is vital in order to move beyond a type of Common that sounds very 'schoolish' and stilted and to understand everything going on around you.

Defective statements were recognised very early in the history of Common. Peter K. Davidson designed Common to have a very complicated and above all structured syntax, and in fielding requests from the Hillbillies production staff for phrases for signage, he quickly realised that no one would realistically write out a phrase like 'Si an fo zra xut zu si karo' on a STOP sign - they would just write SE KARO or even just KARO. SE KARO is proper of course, but KARO is defective, and Davidson by his own account came to believe that Common speakers would use defective forms quite often in casual speech or in necessarily terse forms of communication like signs.

Davidson, therefore, coined the terms 'proper statement' and 'defective statement' in order to discuss this concept with fans of the show. The English terminology survived Davidson's weakening control of the language and his eventual demise, and remains the way we talk about this idea in English.

In Common, in school education, a sentence is called 'ny wasko', a 'thread', and people are taught to always spin the correct elements into the thread. In the academic study of language, however, scholars prefer the term 'ny xof', an assembly, which translates what Davidson called a 'statement'. This can come in two varieties - 'ny rowéteras xof', 'a compliant assembly' and 'ny ikrowéteras xof', literally 'a noncompliant assembly'. These are Davidson's proper and defective statements, respectively.

Proper Statements

We will start the discussion of defective statements by first exploring what is a proper statement. Put simply, a proper statement is any utterance that obeys all the syntactical rules of Common to be a grammatical and complete sentence. The smallest proper statement possible is one word, as in this example:

Hapo.

This could mean, 'The chimpanzees threw fish to the cats', 'Trisha gave David a present', 'Joe asked Sarah for a cup of coffee', a virtual infinity of possible meanings depending on context, but in reality would only be uttered by itself as a positive confirmation of something already throughly established by context, or as a crude way of saying just 'give'. It is a form of the ditransitive auxiliary 'hap'.

Learners might get the idea that defective statements are short and to the point and proper statements are wordy and detailed, but in fact proper statements can also be highly condensed and context-dependent. They are just strictly limited in what they can or must contain and how they are structured.

With Common's pro-drop structure, the only mandatory element a sentence has to have is a verbal auxiliary. The subject and predicate are not needed, nor even is the content word that specifies the action  of the verb - it suffices simply to declare the kind of argument structure of the sentence.

Building from there, the statement is proper as long as it obeys the syntactical rules of Common - nouns are phrases with an article determiner and a head term, verbs are phrases with an auxiliary determiner and a head term, and the head terms may be omitted as long as there are no modifiers or modifying terms present, but if there are, a head term or the dummy term 'yn' are required. Any of the verb's declared arguments can be omitted, and there must be no undeclared arguments - for example, a transitive skurun verb using 'te' as the auxiliary cannot have a dative object present or it is not proper.

Defective Statements

Defective statements are statements that violate the rules of what makes a proper statement. There are a number of kinds, and they are not all equally probable. Some examples:

• No verbal auxiliary, or no verb phrase in the statement
• Terms used without a determiner.
• Modifiers used without without a noun or verb phrase to attach to.
• Modifiers (typically third grade with no object) used with a defective noun or verb phrase that is missing either its determiner or its head term.

Defective statements, nyz ikrowéteras xof, contrast with merely ungrammatical statements, nyz ikhílinys xof. Defective statements are not actually considered ungrammatical per se by Common linguists. Defective statements serve a purpose, they pass muster with native speaker intuition, and they are not a free-for-all, there are specific patterns to their usage that just happen to  be outside Davidson's original syntactic design for the language. Some examples of simply ungrammatical Common that native speakers will agree sounds wrong:

• Zero deriving a modifier into a term or a term into a modifier. Common speakers do not like ambiguity as to whether a word is a term or modifier.
• Violation of the mandatory head term rule when modifiers are present in a phrase if the modifiers have objects or if there is any complexity at all to the phrase.
• Extra, undeclared verbal argument used in the statement.

The types of errors in the 'ungrammatical' category are perceived as errors and not merely short or clipped speech. In fact, they are typically speech errors or L2 errors. Adding an undeclared argument, for example, can happen when a person misspeaks and uses the wrong auxiliary with a verb, and it is a common L2 learner error (interestingly, children very rarely make this error beyond a very young age).

Actual defective statements, however, are frequently employed by native speakers, in set phrases, on signage and notes, in quoting people, and in a number of other contexts. In the rest of this section we will talk about some of the places where defective statements are used, and the rules and patterns for their use. We will also link to articles that go into more detail on specific areas where they exist.

General Characteristics

Here are some general patterns to watch for in defective statements:

• With signage, there is often an unspoken 'zu/ju sy' addressing the reader simply assumed, or abbreviated ZS or JS.
• The hortative 'fo zra' is often omitted in defective instructional statements or abbreviated FZ when trying to be polite - ironic in that 'fo zra' is itself defective.
• If the there is no verb, nouns will tend to have the case they would have if an appropriate verb were present. An ergative noun implies the thing it's labeling is going to do or cause something, an absolutive noun implies you're supposed to do something with the thing it's labeling, and a dative noun specifies something you're supposed to go towards or put something in.
• If a noun is supposed to be interpreted without an implied action, as when simply naming something, or calling out to someone, the nominative is used.
• A modifier used defectively often adheres to an invisible 'se an' or 'si an', as in the popular NWO propaganda expression 'A LSO Awnys', 'New World Order Forever' - you know that 'awnys' doesn't belong to 'a LSO' because it is in the wrong position. LSO takes the absolutive case for this assumed but omitted verb. One may sometimes see an abbreviation SA for 'se an' as well.

Hortative 'Fo Zra'

See attached article. 'Fo zra' evolved during the modern period from the set phrase 'si an fo zra xut...', which became shortened down to 'fo zra xut' or more commonly in casual speech, just 'fo zra' (sometimes abbreviated on signate FZ or omitted entitely). Fo zra is considered a defective statement in that from its origins it is clearly not an adverbial phrase of the main verb.

Benefactive Dative

The Common dative case can sometimes have a benefactive sense, marking the beneficiary of an action, as in the benefactive valence shift, where a skurun verb is used with a happat auxiliary and a dative beneficiary argument is added to the sentence.

Common also has a dative construction that is often used as a possessive along with a relativiser. Example: 

Na majt su ija pikki nox

The cat's toy

These senses can become conflated, and the dative possessive is likely to be chosen for benefactive kinds of possession, where English might use a "for" expression. Example:

Ny caf su ijaz ikpératys atuin nox.

A seat for disabled people. 

This type of phrasing is also used in defective statements such as signage explaining that something is 'for' someone. The above would often be seen shortened to: 

Nar caf ijaz ikpératys atuin

Handicapped seating

Common speakers will generally hear and read this kind of construction as a shortened benefactive applying to the main noun, rather than as a dative argument to a missing verb.

This can even be seen in more formal contexts such as the names of organisations. This is a real example. There is a particular Epekwitys charity which is called "Choices for Youth" in English that helps young people with recovery from addiction and mental health issues. It's Common name could be 'Nyz Tun Upána Naz Welun', using a prepositional phrase similar to English, and that would be completely unremarkable. However, its name is actually 'Nyz Tun Ijaz Welun', a defective statement with a benefactive dative, and this raises few eyebrows in terms of how it is perceived as grammatical Common.

Signage

See the attached article on signage. Defective statements are more the norm than the exception on signs, especially signs expected to be read and obeyed quickly, or to name something.

Quotations

Paraphrases in Common are often proper. For example:

Ja pocuk hapo zisse si a slek ija pikki hyp.
The child said they would feed the cat.

The paraphrased quote is introduced with the verbal relativiser 'si' in the absolutive case, linking it to the main verb as required, and it obeys the verb-final preferred syntax of a dependent clause. However, direct quotes are usually defective:

Ja pocuk hapo zisse, "Je hap a slek ija pikki."
The child said, 'I will feed the cat.'

This is considered defective because the quote is like a dependent clause of the main idea, 'the child said', but there is no grammatical linker to tie it to a role on the main verb, and the syntax of the quotation is completely free, with no verb-final preference. It's a 'missing determiner' type of defective statement. Notice as an aside that the quotation is in the old American English style of inverted commas.