There is an ocean of difference between colloquial conversation in real life and the dialogue that appears in Shakespeare's works, even when his plays are at their least artificial and most mimetic.
In its most ordinary use, the word "conversation" means nothing more that the talk in which real men and women engage in the greater part of their social lives. These conversations might include formal or semi-formal events such as oration, debate, interview, negotiation, interrogation, official inquiry, ceremony , arbitration, sermon, lecture etc. -- all of them linguistic interactions that are governed by specific although for the most part unarticulated rules. "Colloquial" conversation, on the other hand, refers specifically to the wave of informal, unplanned, unregulated and unrehearsed exchanges that occur over dinner, on the street, by the water-cooler, at the tavern. Such conversations, although not incapable of eloquence, are on the whole disorderly, sprawling and haphazard. They are brimful of uncompleted or suspended thoughts (or thoughts introduced by one interlocutor and then either completed or re-directed by another), with syntactic collapse and improvisation , with references to shared experience that may seem to be grand leaps of logic to an eavesdropper but that are perfectly intelligible to the participants, with mumbles and grunts, extended pauses (some meaningless, some momentous), with apparently inexplicable ellipses, with overlaps in which a number of participants speak simultaneously, with unmediated zigzags from the profound to the trivial, with repetitions and backtracks, with mis-speakings, mis-hearings, clarifications, false starts, fragments, non-verbal but sometimes significant ecphoneses or "response crises" (ooh-ooh), and with a flotilla of other very ordinary and very natural curiosities. Real colloquial conversation is spontaneous; it is the activity of two or more intelligences working together to shape meaning. Real talk is essentially untranscribable, and students of conversation who have made an effort to set such interactions down on paper have had perforce to resort to elaborate and imperfect diagrams and codes.
In strong contrast, dialogue in Shakespeare's plays very seldom attempts to approximate colloquial conversation. And with good reason: Elizabethan dramas seldom stoop to represent the casual situations in which conversation is likely to occur. Instead, the circumstances upon which the plays dwell are typically formal or ceremonial, and the dialogue in which they are enacted consists for the most part of speeches that delineate an emotion or moral response to a conflict, of debates over the proper course of action, of reports on past or distant events, as well as judicial or ritualistic confrontation, soliloquy, meditation, prayer, boast, threat and counter-threat and various other kinds of regulated discourse in which the artless and random quality of ordinary talk would be entirely inappropriate. The dialogue in comedies, though in a different register, is equally artificial, consisting as it does, of wit-combats, jests, and the conceits that clownage keeps in pay. Shakespeare's most colloquial exchanges, unlike real-life conversation, are on the whole orderly, sequential, composed in intelligible syntax and in complete thoughts. It goes without saying that dramatic dialogue is, with the exception of the rare improvisational moment, not spontaneous at all but the studied product of a single controlling intelligence.
During the first years of his career as a playwright, Shakespeare experimented with a variety of revolutionary ways to compose dialogue (not generally, but on propitious occasions) that, although not in any real sense congruent to actual spoken conversation, nevertheless managed to create the illusion of a natural and colloquial sound. The employment of dialogue that might pass for real utterance was not an inheritance from earlier dramatists but was a craft that Shakespeare had to develop on his own. The fabrication of such dialogue is an unobtrusive art that does not call attention to itself -- in point of fact, colloquial conversation is most successful when it is least noticeable. While the great leviathan examples of Shakespeare's rhetorical mastery have been subjected to exhaustive analysis, colloquial conversation is so small and so inconspicuous a fish that it has managed for hundreds of years to slip the nets of critical analysis.
There is a finely-crafted instance of seemingly-natural colloquial conversation in Othello.
As Emilia helps Desdemona prepare herself for bed, the two women gingerly feel their way toward an issue of great sensitivity -- the domination of women by men. It is a relaxed and intimate conference, all the more obviously so because it follows in the wake of an anguished and highly-wrought -- and rhetorically elevated -- scene in which Desdemona has been slandered as an adulterer and as a daughter of the game.
What techniques does Shakespeare employ to make the exchange between Desdemona and Emilia appear quite so marvelously natural?
Attempting to console her sorrowful mistress, Emilia offers the opinion that it would have been better if Desdemona had never known Othello. Desdemona contradicts her serving-woman:
Des. So would not I: my love dost so approve him,
That even his stubbornness, his checks, his frowns
(Prithee unpin me) have grace and favor.
"Prithee unpin me" comes as a genuine surprise because it is syntactically discontinuous from the sentence in which it is embedded. It's a separate topic. Dialogue in Elizabethan drama ordinarily deals with issues sequentially rather than simultaneously, but dialogue begins to sound a bit like conversation when the interlocutors engage more than one subject at at time. That the two themes of the discourse are located on different rhetorical levels (the rather formal series of nouns in parallel -- stubbornness, checks, frowns-- in contraste to the offhand parenthetical instruction), suggests that something interesting and different is about to occur.
The progress toward real or realistic-sounding conversation, initiated with "unpin me here," continues when Emilia's response engages neither Othello's mysterious anger or Desdemona's unpinning, but introduces a third subject: "I have laid those sheets you bade me on the bed." With this sentence Emilia does more than simply resume a discussion of so ordinary a matter as bedclothes, she also replicates a common feature of colloquial conversation -- its practice of referring without overt signal to a past mutual experience -- i.e. "you bade me."
Now Desdemona drifts off in a direction of her own.
All's one: good faith, how foolish are our minds?
If I do die before, prithee shroud me
In one of these same sheets.
"All[s one" -- with its variant "all's one for that" is a common Elizabethan demotic catch phrase: here it serves a meaningless filler. Desdemona's meander from death to shrouds to sheets is designed to reflect her own private, internal non-volitional synaptic leaps. Her apology - "how foolish are our minds" - reflects both Desdemona's and Shakespeare's knowledge that the sentences violate the habit of dramatic dialogue in that they are ordered not by logic but by association.
Emilia's mild but polite rebuke ("Come, come, you talk") is followed by a sentence in which Desdemona introduces the fourth separate and distinct subject of this unfolding conversation.
My mother had a maid called Barbary.
She was in love, and he she loved proved mad,
And did forsake her.
Desdemona has fallen into a reverie in which she re-lives an experience of the childhood that Shakespeare has newly and spontaneously invented for her. In these two-and-a-half lines, Shakespeare audaciously allows Desdemona to introduce three new but extremely pertinent characters: Desdemona's mother, hitherto unknown to the audience, her mother's forsaken maid Barbary, and the maid's lunatic and inconstant lover. The effect of Desdemona's brief but poignant recollection is to reinforce the illusion that she is an autonomous speaker, giving shape to her sentences as they precipitate out of her battered and not-entirely-disciplined consciousness. An astute audience (or readership) will certainly notice that Desdemona projects her own plight onto these imaginary meta-beings, and although the psychological ramifications of their creation are rich indeed, Shakespeare's use of these improvised beings to mimic the habits of real talk is as fully wonderful.
She (.e. Barbary) had song of willow.
An old thing 'twas, but it expressed her fortune.
And she died singing it. That song tonight,
Will not go from my mind. I have much to do
But to go hang my head all at one side
And sing it like poor Barbary.. Prithee dispatch.
To enforce the quotidian quality of the dialogue, Shakespeare invokes a phenomenon familiar to every reader or hearer: the tune that seems to repeat of its own accord in one's mind. The result: Desdemona has been provided with a memory, and her memory holds a song, and that song is now apparently going to sing itself independent of the character's own will. But what occurs is not only the illusion that Desdemona reveals an inner experience; it is also that these reflections are cast in such courageously monosyllabic language. And just to assure us that the characters not not float from their dock in the material universe, Desdemona's instruction to Emilia --"Prithee dispatch" - sustains the exact colloquial mode initiated by "Prithee unpin me" and anchors both women in the real present.
Both song and reverie are now shunted aside as the conversation comes to a small climax. The two ladies contineu to imitate the randomness of real talk:
Emelia. Shall I go fetch your nightgown?
Desdemona. No, unpin me here.
This Ludovico is a proper man.
Emilia. A very handsome man.
Desdemona: He speaks well.
Emilia: I know a lady in Venice would have walked barefoot to Palestine for a touch of his nether lip.
Desdemona and Emilia drift from topic to topic: nightgowns leads by some unarticulated but easy-to-imagine route to Ludovico and his masculine allure, thence to Ludovico's habits of speech and at last to the very vivid and memorable 'lady in Venice" -- a colorful personage who springs from Emilia's fabricated pre-history, and who flashes across the stage in a hyperbole of brilliant but unstressed beauty (and whose inexplicable passion asserts that women can prosecute love-longing fully as irrationally as men). And then, just when it seems as if the maid Barbary has been left in the lurch and forgotten, the conversation turns back upon itself and Desdemona breaks into the song of the poor soul who sat sighing by a sycamore tree. To reinforce the apparent spontaneity of the moment, Shakespare makes Desdemona repeatedly interrupt (and even amend) her own singing : "Lay by these"... "Prithee high thee; he'll come anon"... "Nay that's not next. Hark who is't that knockes." This broken series of syntactically independent units, periodically intruded into the song, are invented for the sole purpose of giving emphasis to the naturalness and immediacy of the moment.
Shakespeare has therefore created the appearance of spontaeous conversation by forsaking the straight path of normative dramatic dialoge. Desdemona and Emilia intertwine present and past, real and fanciful, public and private, high language and low, song and speech, understatment and exaggeration, syntactic coherence and syntactic collapse, all within a context of shared knowledge and almost sisterly intimacy.
The colloquial moment is fleeting, for even before the scene comes to a close, Shakespeare returns to a more traditional dramatic idiom. Nevertheless, the episode has done important work: Emilia's great feminist manifesto ("Let husbands know,/ Their wives have sense like them") which will follow immediately after this exchange, has been so effectively grounded in a real, earthy, and contemporary context that it must stir every sensitive intelligence with its grand appeal to equity.
It has long been acknowledged that the exotic Moor speaks in a highly particularized, elaborate, and picturesque idiolect of his own - the music that sweeps in with the icy currents of the Pontic sea and allows the Moor's great dignity to find its expression. Desdemona and Emilia sing a far calmer but more original song, and their impromptu domestic duet is surely no less and perhaps even a greater artistic achievement than Othello's stupendous arias.