Basics
The Cypriot dialect is a set of mutually understandable variants of the Greek dialect spoken in the island of Cyprus (the Republic of Cyprus to be precise).
All variants share common characteristics (I will elaborate below) but they have their unique traits as well. For some decades now these variants are in the process of merging with the neutralized Cypriot Greek which resembles to Standard Greek more than it used to do in the past. All dialects eventually die I guess
Politicolinguistic status
Cyprus is basically in a diglossic situation.
Standard Modern Greek is taught at schools and utilized as the official language but the Cypriot dialect is the language used for everyday communication.
Use of the dialect in formal settings is discouraged but not uncommon.
Writing
There is no standard spelling for the Greek dialect.
This becomes even more complicated when one wants to write down sounds that exist in the dialect but are missing from the Greek alphabet. He may resort in ad-hoc combinations or the Latin alphabet (with English readings).
Generally: σσ/σι+vowel = ʃ, ζι = ʤ, τζ/τζι = ʧ, ʤ (these combination would be normally pronounced as /s:/, /si/, /zi/, /dz/. Ambiguities occur)
Phonology
There are 5 vowels, /a/, /i/. /e/. /o/, /u/, same as in standard Greek. The fun begins with the consonants.
As explained in Wikipedia
1. Double consonants preserved the stressed pronunciation of Ancient Greek.
1. Double unvoiced plosives (ττ, ππ, κκ) are pronounced aspirated ([tʰ], [pʰ], [kʰ] or [cʰ] depending on the succeeding vowel). More accurately [t:ʰ], [p:ʰ], [k:ʰ] or [c:ʰ]
2. The rest of the double consonants are pronounced as geminates. (e.g. λλ as [lː], μμ as [mː], etc.)
2. Extreme "palatalization" of Greek velars to palato-alveolars when followed by the front vowels [e] and and the semivowel [j], very similar to how standard Italian developed from Latin. It should be noted that Standard Greek pronunciation exhibits true palatalization of velars to palatals ([k] > [c] and [x] > [ç]). The palato-alveolars in Cypriot Greek can be found both as affricates ([tʃ]) and fricatives ([ʃ]):
1. The "palatalization" of kappa, i.e. κ > κ̌
Standard Greek [c] becomes a soft affricate [tʃ]. This sound is usually represented with τζι or κ̌. For example, Standard Greek καί [ce] meaning "and" becomes Cypriot Greek τζιαί or κ̌αί [tʃe]. Also Standard Greek εκείνος [eˈcinos] becomes Cypriot Greek κ̌είνος [ˈtʃinos]. Note however this is not a hard and fast rule (counter-examples include loans from Standard Greek: κηδεία, κέρδος, άκυρο, ρακέττα).
2. The "palatalization" of kappa after a sigma, i.e. σκ > σ̌κ̌
Standard Greek [sc] becomes the double fricative [ʃː].
3. The "palatalization" of double kappa, i.e. κκ > κ̌κ̌
Pronounced in Standard Greek as single [k] in Cypriot Greek it becomes an aspirated affricate [tʃʰ].
4. The "palatalization" of chi, i.e. χ > χ̌
Similarly Standard Greek [ç] becomes [ʃ]. This sound is usually represented with σι or χ̌. For example, Standard Greek χέρι [ˈçeri] meaning hand becomes Cypriot Greek σιέρι or χ̌έρι [ˈʃeri].
3. Voicing of φ, θ and χ (aspirated consonants in Ancient Greek) before liquids and nasals, to β, δ and γ respectively. (e.g. γρόνος (Cypriot dialect) instead of χρόνος (Modern Greek) (= year), άδρωπος (man) (Cypriot dialect) instead of άνθρωπος (Modern Greek) (= human). In Cypriot dialect άδρωπος means man and not human. Ηuman is called πλάσμα.This process is partially reversed in younger speakers due to the influence of Standard Greek.
4. Deletion of β, δ, γ, voiced intervocalic fricatives; e.g. κοπελλούδιν > κοππελούιν "little child". In linguistic texts, the deleted fricative is sometimes put in brackets for clarity: κοππελού(δ)ιν.
5. /x/ > /θ/: e.g. άνθρωπος > άχρωπος "human"
6. Defrication of [ʝ]/[ç] that function as semi-vowels in Modern Greek to [c] with most of the time modification of the preceding consonant. (e.g. ποιός [pços] in Cypriot Greek would be pronounced as πκοιός [pcos], σπίτια [ˈspitça] in Cypriot Greek would be pronounced as σπίθκια [ˈspiθka]). This is carried further in some parts of Cyprus where speakers use e.g. πσοιός [pʃos]
7. External sandhi rules for word-final nasal consonants:
1. /n/ before bilabials becomes [m]: e.g. το μωρόν [to moron] the baby (acc.).
2. /n/ before velars becomes [ŋ]: e.g. την κρατικήν [tiŋ ɡratiˈcin] the governmental (acc.).
3. Standard Greek sandhi rules for word-final [n] do not apply to Cypriot Greek; the /n/ is used much more frequently in Cypriot Greek.
8. The vowel eta η is in some words pronounced which according to the Erasmic understanding is ancient Greek. A basic common example would be μην in Cypriot, μεν.
In short:
consonant length matters (a warning though: not all the long consonants are preserved and many words are pronounced with long consonants even if etymologically they are short)
aspirated consonants exist (but not related with the ancient greek ones)
consonants ʃ, ʧ, ʒ, ʤ exist
deletion of the "weak" consonants
extensive use of the "final nu"
Grammar
An attempt to write a grammar textbook for the dialect is made by blogger Κυπριακόφωνος.
Personally I disagree with some parts, which is natural. He's a speaker of the Larnaca variant and I speak the Kokkinochoria dialect
http://www.megaupload.com/?d=89JNI8A9
[i]Redistributed with the permission of the author.
Some major difference from the Standard Greek are
*Extensive use of infinitives as nouns
*Past tense augmentation (ε-) is the standard and not the exception
*"to be" verb is conjugated a bit different
είμαι, είσαι, ένι/εν, είμαστην, είσαστην, ένι/εν. The standard forms (next line) are becoming common though.
είμαι, είσαι, είναι, είμαστε, είστε, είναι
*Personal pronouns differ in pronunciation and their weak type are used in a different manner
About the weak types. In standard Greek, when you want to say "I love you", you say σε (σ') αγαπώ).
This sounds weird to Cypriots. We say "Αγαπώ σε".
Weak types of the pronouns always go after the verb in affirmative or interrogating sentences in Cypriot Greek. Regular order is used for negation. Έν σε αγαπώ.
Various other grammatical stuff:
*Negation particle μην is pronounced μεν
*Negation particle δεν is pronounced εν (same as the "is" verb. I write έν for δεν to distinguish these two)
*Periphrastic future auxiliary is εννά instead of θα
*Periphrastic past tenses are generally avoided. Έχω πάει and είχα πάει are expressed with a plain ol' Aorist, επήα (>επήγα). This causes hypercorrection (have you ever watch Greek talent shows with Cypriot players? Their Std. Greek sounds weird to Greeks and Cypriots alike).
Vocabulary
Cyprus has always being conquered by other nations. This gave to the cypriot dialect lot of new words. Latin, Old French, Italian/Venetian, Arabic and Turkish.
At the same time it retained many ancient greek words that are obsolete in Greece. This is due to the isolation of the island.
Nowadays more new words came from English and Std. Greek (since most media is imported from Greece).
Some words that are "trademarks" of the cypriot dialect are:
συντυγχάνω (v., /sindi'xan:o/): to chat (from Ancient Greek: συν + τυγχάνω = to exist at the same place)
βλαντζί (n., /vlan'ʤi/): liver, Std Greek. συκώτι (from French "flanc")
(α)γιουτώ (v., /(a)ju'to/): to (be a) match (from Italian aiutare)
δικλώ (v., /ðik'lo/): to look towards smth (Medieval Greek βιγλώ>βίγλα)
ζόλος (n., /'zolos/): unpleasant smell (not sure for the etymology)
λάλλαρος (n., /la'l:aros/): extreme heat (»», ήλιος?)
λαφαζάνης (n. adj., /lafa'zanis/): one who tell fat lies (not sure for the etymology)
νεκατσιώ (v., /neka'ʧo/): to loathe
πατανία (n., /pata'nia/): blanket, Std Greek κουβέρτα (from bataniye, Turkish)
παττώ, παττίζω (v., /pa'tʰo/, /pa'tʰizo/): to bankrupt (Turkish battim)
ρόκολος/α (n., /'rokolos/): brat, teenage boy (-ος) or girl (-α)
συνάω (v., /sin'ao/). to collect (A.Greek συν + άγω)
τσαέρα (n., /ʦa'era/): chair (Venetian charegla)
τσιλλώ (v., /ʦi'l:o): to push, to run over smth (not sure for the etymology)
You can browse http://wikipriaka.com/ for more words but don't trust the etymology section blindly
Any questions?