The idaafa's mirror, structure-wise, is the equational sentence: the first term is defined; the second may not be. What's nice about equational sentences is that, in the present tense at least, there are no verbs.
You can ask someone how he or she feels, say how you feel, ask directions, ask a price, tell an acquaintance how many children you have, ask how many children your acquaintance has, ask how the children are, all without using a single verb. All you need are nouns, adjectives, prepositions, and a few question words.
The equational sentence consists of, as noted, first a defined subject: a name; a pronoun (such as /huwa/, "he"); or a noun phrase, the latter defined either by a definite article or a possessive pronoun suffix (such as /-iy/, "my," /-hu/, "his," /-haa/, "hers"). This subject is followed normally by an undefined subject complement (another noun phrase, or an adjective phrase), which describes the subject.
Indefinite Inflectional Ending
The indefinite ending of the noun (and modifying adjectives) in the complement, the ending /-un/, is somewhat important and is often pronounced. Equational sentences are translated into English as sentences conjoined with a form of "be:" /hiya ?aalibat-un/ (she student-nominative indefinite ending) means, "she's a student" (this becomes /huwa ?aalib-un/ for a man).
Note that when the noun is modified by an adjective (in the subject part if the noun is the subject;in the complement part if the noun the complement), both must be definite, or both indefinite. For example, the English sentence, "the Yemeni teacher [meaning the teacher from Yemen] is new," can be rendered in Arabic as, 'al-'ustaadh-u (the-professor-nominative definite ending) [']al-yemen-iy[-u] (the-Yemen-adjective[-nominative definite ending]) jadiyd-un (new-nominative indefinite ending).
/'Al-yemin-iy[-u]/ (the-Yemeniy), like /'al-'ustaadh-u/ (the-professor or teacher), is preceded by the definite article /'al/. In Arabic, if a noun is defined, so is the adjective that modifies it, and that adjective must be preceded by /'al/.
If the noun is not defined, it ends in the indefinite suffix /-un/ (nominative case). Its modifying adjectives likewise end in /-un/ and are not preceded by /'al/. In equational sentences, both the nominative definite marker [-u] and the indefinite marker [-un], may be pronounced for emphasis.
If a noun in a sentence is modified by a possessive pronoun, for example, kitaab-iy (book-my) [']aj-jadiyd-u (the-new-nominative definite marker) ?a"b-un (difficult-nominative indefinite marker; English, "my new book is difficult"), the adjectives modifying the noun /kitaab-iy/ (those that are in this case in the subject part of the sentence, where the noun /kitaab-iy/ is) are of course preceded by /'al/, but do not take the possessive pronoun suffix. Only the noun takes a possessive pronoun.
Equational Sentences: Subjunctive?
Since the verb is omitted in equational sentences, you don't need to worry about the verb's subjunctive form. Let's look at an Arabic greeting, 'as-salaam[-u] "alay-kum (the-peace [be] upon-you, plural; which means "peace be upon you," or "may peace be upon you"). This greeting is translated with a subjunctive verb "be" in English. There's no verb in the Arabic.
Also, /-kum/ functions like a "royal" plural here. When I say /salaam/ to you alone, I still say 'as-salaam "alay-kum and not 'as-salaam "alay-ka (for you singular, masculine) or 'as-salaam "alay-ki (for you singular, feminine).
Equational Sentences: Past Tense
In the past tense, there is a verb form meaning "was" or "were," and this verb is needed between the subject and complement. The verb is /kaana,/ which is conjugated as /kun-tu/ (was-I), /kun-ta/ (were-you; for a man), /kun-ti/ (were-you; for a woman), /kaan-a/ (was-he), /kaan-at/ (was-she), /kun-naa/ (were-we), /kun-tum/ (were-you plural), /kun-tunna/ (were-you plural; for women), /kaan-nuw/ (were-they). For more, see: Rutgers' University's information.
The Arabic verb "dwell" /sakana/ (dwelled) is formed from the verb /kaana/. Verbs formed from /kaana/, unlike /kaana/ itself, need to be used even in the present tense. /Kaana/ is used only in the past tense.
Equational Sentences With Prepositions
It's possible to begin an equational sentence with a preposition: "and-iy (for-me) qalim-un (pen-nominative indefinite); in English, "I have a pencil [or pen]." Another example is: la-hu (for-him) kitaab-un (book-nominative indefinite). Both /"and-/ and /la-/ indicate ownership. A common Arabic proverb for example is /la-kul, yawm-u-hu/ (for-each, day-nominative definite ending-his), "for each, his day:" ??? ????
Note that in the last sentence the complement was actually defined by the possesive pronoun /hu/. It can be either here. Common prepositions include: /"and-/ ("for," possession), /la-/ or /li-/ ("for," belonging with), /fiy/ ("in," "on top of"), and /"alaa/ ("upon"). These prepositions are followed by a noun or pronoun. Together, these form the subject.
Other Equational Sentences: Questions
Interrogative words also begin equational sentences. For example, 'ayna (where) mabnaa (building) ['a]j-jami"a[t-i] (the-university-genitive definite marker)/ means, "where is the university housing?" (or student dormitory).
In the question, word order is normally inverted. Thus it's the last term in the sentence, which by the way is the actual subject, that is defined, /mabnaa ['a]j-jami"at[-i]/. /Mabnaa 'aj-jami"a[t-i]/ is actually an idaafa, with /mabnaa/ in some way being possessed by and hence modified by /'aj-jami"a[t-i]/ (the-university-genitive definite marker). The undefined term in this sentence is the interrogative word /'ayna/.
Common Arabic question words include: /"ayna/ ("where"), /mataa/ ("when"), /maadhaa/ ("what"), /maa/ ("what;" /maa/ is a short form, and is often used to say "what['s] that?" /maa haadhaa?/), /li-maadhaa/ ("for-what," "why"), /li-ma/ ("for-what," "why," short form), /man/, "who" (/man/ is the question word "who;" there are other words meaning "who" when "who" is a relative pronoun), /kayfa/ ("how"), /kam/ ("how much"), and /'ayyu/ ("which").
Arabic question words translate almost exactly into English question words. Here are sample questions:
/'Ayyu/ is different than other question words. Like the definite article /'al/, it precedes a noun. Again like /'al/, /'ayyu/ normally does not precede a pronoun: 'ayyu ?alib ?alib-un fiy jami"at-i [']il-Qahira[t-i]? ("which student[-nominative indefinite marker] student-nominative indefinite marker in university-genitive indefinite marker the-Cairo[-genitive definite marker]?"). Note that word order is not inverted: /'ayyu ?alib/ is the subject of this sentence (I've omitted the inflectional ending entirely for /?alib/ as I've never heard it used.)
Other Equational Sentences: Negations
It's possible to negate equational sentences. To do so, you need a form of /laysa/. /Laysa/ means "he's not," or "it's not." /Laysa/ is grammatically a combination of the verb "be" and "not." It's used in the present tense only, and differs from the negators /lan/ ("will not," used with a verb), /laa/ ("do not," with a verb) and /lam/ ("did not," with a verb). Unlike these three negators, /laysa/ precedes no verb. It's also "conjugated," just as if it were a verb, whereas the other three markers are not conjugated (the accompanying verb is conjugated).
Conjugations of Laysa
Singular conjugations of /laysa/ are perhaps more common than plural. These are: /las-tu/ (be not-I), /las-ta/ (be not-you masculine singular), /las-ti (be not-you feminine singular), /lays-a/ (be not-he or it), /lays-at/ (be not-she or it). You can see all conjugations at: Desert-sky.
If the subject of /laysa/ is a non-human plural, the feminine singular form is always used, regardless of whether the subject precedes or follows it. To say, "the letters (correspondance) are not with me," that is, "I don't have the letters," I say, laysat ma"-iy 'ar-rasa'il-u (Isn't-feminine singular marker with-me the-letters-nominative definite marker).
Ghayr Versus Laysa
I personally prefer the negator /ghayr/ to translate the English sentence above: ghayr ma"-iy 'ar-rasa'il[-u] (not with-me the-letters[-nominative definite marker]). /Ghayr/ is not conjugated: unlike /laysa/, /ghayr/ is invariant. Note that word order is inverted here: /'ar-rasa'il[-u]/ is the sentence subject, but it comes at the end.
Human Versus Non-human Plurals
"The letters/correspondance are not here," in Arabic, is either 'ar-rasa'il-u lays-at hunaa or lays-at hunaa 'ar-rasa'il-u. Whichever word order you use, the feminine singular form /laysat/ is of course used for non-human plurals. (With human plurals, rules differ.)
Negating the Past Tense
The past tense verb, /kaana/, incidentally, is not negated with /laysa/. It's negated with /lam/ ("did not"). When negated, instead of the perfect stem of /kaana/, the imperfect stem is used. The imperfect stem looks a bit different than does the perfect: to negate kaan-a hunaak (was-he there), you say, lam ya-kun hunaak ("didn't he-be there").
A note: in Arabic there are two verb stems for every verb, a perfect stem (for completed action) and an imperfect stem (for action not yet completed). The negator /laysa/'s conjugations look like the perfect stem's. The perfect is conjugated with the endings /-tu/, /-ta/, /-ti/, /-a/, /-at/, /-naa/, /-tum/, /-tunna/, /-uwn/, /na/. But /laysa/ refers to the present!
"Topicalization" in Equational Sentences
It's also possible in Arabic to say: "ayna-hu (where-it) mabnaa (building) 'aj-jami"at-i (the-university-genitive definite). In this case, the pronoun suffix /-hu/ ("he," "it") serves to topicalize the /mabnaa/ (building, dormitory) you're asking about. This translates into English perhaps as, "where is it? the university housing?" You might say this in spoken English, but would not normally write it (except when writing dialogue). In Arabic, you can write this. Here are more examples:
The above sentences, pronounced as written, sound rather strange in Arabic, because of /-u/ (the nominative definite marker), which should not be pronounced. Drop the /-u/ endings. But pronounce clearly the vowels in the suffixes /-hu/ and /-haa/ ("it," masculine or feminine), and also the vowel in the following article /'al/ ("the"). The vowels in the pronoun suffixes /-hu/ and /-haa/ do not merge with the vowel in/'al/. (However, for /jami"at-u 'al-qahirat-i/, an idaafa meaning, "the University of Cairo," the /-u/ ending of /'al-qahira[t]/ is dropped, to become: /jami"at-u 'al-qahira/; also the [-u] which indicates the nominative singular at the end of jami"at-u merges with the vowel in the article /'al/, with the intervening glottal stop /'/ (Arabic hamza), not pronounced. This makes: /jami"at-uul-qahira/.
Pronunciation varies with dialect. For some dialects, such as the Levantine Arabic dialect, the pronunciation of /jami"at-uul-qahira/ does not change much; the consonant beginning the word /jami"a/ changes very slightly and sounds more like the /z/ in /azure/.)
Equational Sentences With a Defined Predicate
Predicates of equational sentences are not always indefinite. But, in Arabic at least, the subject is clearly defined. You begin equational sentences with a defined noun phrase, with a phrase defined by the definite article; or else with a proper name, or a subject pronoun. In English likewise you hardly begin a conversation by saying, "a book is new." But you can say, "the book is new."
So how do you say in Arabic, for example, "that pen is mine?" The predicate, "mine," is definite, and so is the subject "that pen."
To make sure your audience understands this as a sentence, you use the pronoun /huwa/ (which means "he," "it"). /Huwa/ inserted between the subject and predicate indicates a link between the subject, /haadhaa 'l-qalim-u/ (that the-pen-nominative definite ending), and the predicate /l-iy/ (for-me). Thus you say: haadha 'l-qalim[-u] huwa l-iy (that the-pen[-nominative definite marker] it for-me).
You can use other third person pronouns to form equational sentences, depending on whether the subject is feminine or masculine, singular or plural (but use the feminine singular for non-human plurals). In my studies, I've never encountered first or second person independent pronouns linking the subject and predicate. First and second person independent pronouns can be the sentence subject, however.
Equational Sentence With a Pronoun as Subject
To say, "I'm in the office," you use the independent subject pronoun, /'anaa/: 'anaa fiy 'l-maktab[-i] (I in the-office[-genitive definite ending]). I omitted the vowel in the definite article /'l/. The definite article here elides with the preceding vowel in /fiy/, which is already long. Thus, I don't indicate that it's lengthened here by retaining the second vowel. Also, the brackets of course indicate that the genitive definite ending [-i] for /maktab/, "office" is not pronounced.