I should note that they describe (and I will be summarising) the Standard Modern Greek prestige dialect, the dialect that you are most likely trying to learn. It's a dialect that I'm personally not fluent in and you will notice that outside this how-to I inflect Greek nouns a bit differently (especially regarding accentuation patterns).
Modern Greek has a system of three functional cases, namely the nominative (ονομαστική), the genitive (γενική), and the accusative (αιτιατική).
Ancient Greek used to have the dative case, but it has fallen out of use thousands of years ago. Genitive and accusative took over in those context. You are only going to see the dative used in fossilised expressions (eg the adverb εν τω μεταξύ 'meanwhile', also spelt εντωμεταξύ, to reinforce that it's no longer a phrase using the dative, but an adverb).
Modern Greek also has a vocative case (κλητική), used to address a person (by their name or some characteristic, like their profession), and more rarely, non-humans and inanimate objects (especially in poetry — see Greece's national anthem, literally a hymn (addressed) to Liberty). Klairis & Bambiniotis do not examine the vocative along with the three functional cases. I will include a section on that in the future.
Modern Greek also inflects its nouns for number, this is a singular (ενικός) and the plural (πληθυντικός).
Nouns always carry information about their case and number. They do so by fusing the two properties into suffixes.
For example: ο φίλος (nominative - singular), των σπιτιών (plural - genitive) and so on.
(A confession: some invariant nouns do exist, and they are in their vast majority recent loanwords, eg το φαξ, which remains invariant in any case and number.)
2. Noun Classes
Traditionally, we classify nouns in three categories, called "genders": masculine, feminine and neuter. This property of nouns is indeed important as it affects which set of article they take, and they require gender accordance with the adjectives or pronouns they refer to them.
Eg: masc ο αναπαυτικός καναπές VS fem η αναπαυτική πολυθρόνα - neu το αναπαυτικό σκαμνί
But this is where the usefulness of the "noun gender" ends. Nouns conjugate differently depending on their noun class, and noun classes are shared between genders.
To categorise nouns in a way that it will help us learn how to conjugate them with ease, we must take a look on how they actually differ.
Let's take two random masculine nouns and try to conjugate them: ο φίλος and o ταμίας
|Nominative||ο φίλος||οι φίλοι||o ταμίας||οι ταμίες|
|Accusative||τον φίλο||τους φίλους||τον ταμία||τους ταμίες|
|Genitive||του φίλου||των φίλων||του ταμία||των ταμίων|
Did you notice it yet? Our first noun has district suffixes for all three cases, but our second noun seems to have only two suffixes: the endings for singular accusative and genitive coincide, and so do the nominative and the accusative in the plural number. Of course there would never be a confusion in context, even the article is enough clafirication, but this leads us to our most imporant distinction: nouns with two suffixes, and nouns with three, or as we call them in Greek: δικατάληκτα and τρικατάληκτα.
There's one more category though, a subdivision of the two-suffix ones:
|Nominative||το ποσό||τα ποσά||το σώμα||τα σώματα|
|Accusative||το ποσό||τα ποσά||το σώμα||τα σώματα|
|Genitive||του ποσού||των ποσών||τα σώματα||των σωμάτων|
The second noun develops a whole new syllable in some cases! We call those two subcategories: ισοσύλλαβα and ανισοσύλλαβα (invariant and variant number of syllables).
In short: we have nouns that have 3 distinct suffixes for all cases, and nouns that have 2 distinct suffixes for all three cases. Among those with 2, some get an extra syllable in some cases.
We proceed with the conjugation tables.
From here after, I am in the regrettable position to use images from the book instead of BBCode tables, because they are too difficult to use in complex configurations like those I will be needing below.
The stem of the noun will be separated with a dash "-", while zero morphemes will be market as "∅".
Pay attention to accent shifts from case to case, something that happens in high-register words more than others. I will include explanations below.
a. 3 Suffixes - Invariant Number of Syllables
This is by far the most straight forward noun class, and it includes masculine and feminine nouns that end in -ος. The feminine nouns that end in -ος are in their vast majority learnèd words.
Notice that in άνθρωπος and είσοδος the accents shifts to the next syllable in the gen.sig, gen.pl anc acc.pl. That happens regularly in those learnèd words.
b. 2 Suffixes - Invariant Number of Syllables
It gets a bit complicated here. In this class, we have nouns of all three genders.
In the masculine nouns, we find those ending in -ας and -ης and the learnèd -έας.
In the feminine nouns, those ending in -α and -η.
In the neuter nouns, those ending in -ο, -ι, and the learnèd in -ος (with -ς being part of the stem, not the suffix of masc. nouns -ς).
We notice that in the masculine nouns in this noun class, the accent is not shifted to the next syllable in the plural nom and acc, but you can have nouns accented in the ultimate syllable, like o φοιτητής - οι φοιτητές, which will not rhyme with ο εργάτης - οι εργάτες, though the conjugation is identical. The accent is shifted as expected in the genitive plural.
The other thing to notice is the different stress partners between the three categories of masc. nouns ending in -ας: those having a vowel stem, or a consonant stem but only two syllables do shift their accent in gen pl. Those having 3 or more syllables and a consonant stem do not shift their accent up.
Consonant vs Vowel stem
ο στρατώνας - των στρατώνων, ο αγώνας - των αγώνων vs ο λοχίας - των λοχιών
But if the noun with the consonant stem has only two syllables, it behaves like the vowel-stem nouns in -ας (which I will call "normal" as a shorthand):
ο μήνας - των μηνών, άντρας - αντρών
A final note on the masculine nouns in this class, the learnèd words in -έας. They are really not strange at all If you are familiar with Ancient Greek you know that in the Attic dialect, when a stem ending in -ε- received a suffix -ε, it was spelt -ει- due to crasis. Because of vowel shifts, the new sound created by -εε- > -ει- is not as intuitive (yet native speakers don't question it because it's learnèd words), but if you assume an underlying from of *αποστολέες > αποστολείς you will see that the conjugation paradigm is regular. (Actually, in my country αποστολέες/γραφέες/γραμματέες (instead of αποστολείς/γραφείς/γραμματείς) is heard often, but I am supposed to teach you SMG here )
The feminine nouns in this class are fairly regular. We have some feminine nouns in -α that behave differently with regard to stress. You can tell which are those easily: if it ends in -ίδα, -άδα or -όνα, the accent is not shifted to the next syllable. Again, that's not arbitrary, historically they were a separate noun class with different suffixes but in SMG they have merged, retaining only a small quirk. (Those words belonged to the obsolete 3rd Conjugation Class, and they used to be η σελίς, η ομάς, η εικών before becoming η σελίδα, η ομάδα, η εικόνα).
The neuter nouns are very regular here. They all keep their accent were it was in the nominative, except from the little subclass of neuter nouns in -ος, which shifts it up in gen.pl.
That's for the nouns that have an invariant number of syllable, now to the:
c. 2 Suffixes - Variant number of syllables
Those are the real oddballs from the technical point of view. In this class we have nouns ending in -ες a very rare and modern suffix that you will mostly see in loanwords (ο καναπές, ο κεφτές, ο καφές, ο χαφιές etc), but also words that have Ancient Greek pedigree (η λέξη, το σώμα κλπ). But despite the variation, I believe that's the second easiest noun class, after the 3 Suffixes Class.
You can see why we call them ανισοσύλλαβα, ie that they don't have a fixed number of syllables. All of them gain a new syllable in plural, and half of them even gain a new syllable in genitive singular.
Literally no exceptions in the masculine nouns in this class.
In the feminine nouns mostly normal, except that we have some nouns from the historic 3rd Conjugation Class. Those have a stem that ends in the sound /s/. This could be spelt -σ-, -ξ- /ks/ or ψ /ps/. Examples are: η λέξη, η τάξη, η πράξη, η πέψη, η γνώση, η κόπωση etc.
Those nouns have a distinct plural ending in -εις, -εις, -εων, but their genitive singular has a register variation: if you need to be very formal you can say της πόλεως and της πράξεως (do not over do it though: saying της πέψεως would be really odd), but if you want a neutral tone then it's better to say της πόλης and της πράξης.
The neuter nouns are also regular. You have those ending in -α (almost always -μα), and those in -ο and -ον. The accent also shifts in a regular pattern.
4. Exceptions and special cases
What did you expect? There always a couple of nouns that don't fit anywhere. I will explain a few, but I hope that you leave feedback mentioning others I have missed. I will include them by editing the post.
I have already mentioned those nouns that do not inflect at all. In their vast majority they are recent loans, especially those that end in really "strange" (from a Greek Grammar POV) sounds, like φαξ, τανκς, φερμουάρ etc.
Other loanwords look pretty Greek as far as sounds go, but they remain invariant, like το πάσχα, το ταξί, το σιντί (-α and -ι are suffixes you'd expect from neuter nouns). Now, some dialects and especially informal registers allow του πασχάτου, του ταξιού, του σιντιού, but in neutral-register SMG you will want to say του πάσχα, του ταξί, του σιντί.
But they are not only modern loanwords. Some very ancient words are also invariant: the names of all letters of the alphabet. Most of them are very old loanwords from the Semitic languages, and a handful of them are Greek words but are all invariant.
Finally, there are the nominalised infinitives. Modern Greek does not have infinitives of course, but Ancient Greek infinitives can be used as nouns, to signify the concept of the verb they derive from. Eg το λέγειν - του λέγειν (from AncGr λέγειν - to say) used to mean "the ability to talk" or "the ability to talk well".
Now, we have something that could become part of the 2 Suffixes - Invariant Number of Syllables class, if only it had more than a handful of words in it. It's the rare female names ending in -ω, like Μυρτώ, Ηρώ, Φρόσω, Χρύσω, Μαντώ.
Of those, Μυρτώ and Ηρώ are attested in Ancient Greek and has two paradigms, the ancient and the modern paradigm. All others are conjugated in the modern way (unless you are a journalist trying to sound as pretentious as possible).
Only singular number since they are people's names.
|Nominative||η Μυρτώ||η Ηρώ||η Μυρτώ||η Ηρώ|
|Accusative||την Μυρτώ||την Ηρώ||την Μυρτώ||την Ηρώ|
|Genitive||της Μυρτούς||της Ηρούς||της Μυρτώς||της Ηρώς|
5. Your questions
If you have any questions about modern Greek nouns, leave them below and I will try to research them for you. After a while, I will edit this section and include a FAQ.
Also feel free to point out which parts of the guide are confusing and need rewriting.