2nd person?

Second person, Irregular verbs, Future of English

Most of the Indo-European languages have gone through the same process that English did with the second person pronouns. In fact we all started at about the same place.

Language......you singular.....you plural
Latin..............tu.....................vos
Anglo-Saxon..thu...................ye
Old Slavonic...ty.....................vy

(Sorry I don't know Old Celtic-->Gaelic or Sanskrit-->Hindi.)

In Old French the Latin words became "tu" and "vous." Good enough so far. But it somehow became "polite" to address a person you're not familiar with in the second person plural. So you'd say to your buddy "Tu parles francais," but to your teacher, "Vous parlez francais."

Same in Polish and all the Slavic languages. "Ty mlovis polsko", to a friend, "Vy mlovite polsko" to your boss.

Same in English. To a friend, "How art thou," but to the lord of the manor, "How are ye?" But in English it got worse. We gave up "thou" completely, and we changed the nominative case of "ye" into the accusative case, so it's "How are you?" whether it's your pal or the tax collector, and there's no difference between you singular and you plural. Nature hates a vacuum, so in some regions they've invented "You all" or "Y'all" for the plural, in others "You guys." (As one of you mentioned.)

Much worse in Spanish. "Tu hablas espanol," if it's your friend. But "Vos hablais espanol" vanished centuries ago, to be replaced by "Vuestra merced habla espanol," literally, "Your grace speaks Spanish." That was too big a mouthful, and eventually contracted to "usted habla espanol," which gets even more confusing when they abbreviate "usted" as "Vd." Oh, and while "vuestra merced" got shortened, "vos" got lengthened into "vosotros," literally "you others," kind of like "you all." It's seldom used outside the liturgy anymore, but every Spanish class in Spain, Latin America, or foreign countries still teaches us to conjugate verbs in the second person plural: "Vosotros hablais espanol."

Could it get any sillier? Sure! In Portuguese! "Tu falas portugues," and "Vos falais portugues," the ancient forms, are still recognizable. (The Latin F changed to a silent H in Spanish. Spanish "hablar" and Portuguese "falar" are the same word.) The adoption of "your grace" mirrored Spanish: "Vossa merce fala portugues," and eventually contracted into "Voce fala portugues." Just like Spanish, right? Except it didn't stop. "Voce" is no longer considered formal. "Tu" has vanished except in provincial dialects and "voce," which once meant "your grace," is now the familiar pronoun. What do they use for the polite form? You didn't want to ask! "The gentleman speaks portuguese," "O senhor fala portugues." Or "The lady...," which is "a senhora" or "a senhorita," depending on whether the lady is married!

Three cheers for Yiddish. It kept the original German forms. "Du" is familiar, "Ir" is polite or plural. "Du redst yidish," or "Ir ret yidish." And that's as far as it went.

Unfortunately German went absolutely bonkers. "Du" is still used for singular familiar, but "ihr" as plural is strictly for sermons. Somewhere along the way German went for the "your grace" formation like Spanish and Portuguese, and unfortunately I don't know the words for it. Suffice it to say that "grace" is a feminine noun in German. Because the next and final step was simply to say "it" for "your grace," instead of building a contraction like in Spanish and Portuguese, but since German is strict about gender, you have to say "she" to mean "it" if "it" refers to a feminine noun. So "sie," which literally means "she," is used as the polite form of you. But do they say "sie spricht," the perfect translation of "she speaks?" No way! It turns out that "sie" also means "they." (Don't ask, pronouns are crazy in every language.) So they say "Sie sprechen," which means "they speak," to mean "you (polite form) speak. Oh yeah, and the "Sie" is capitalized when it means "you," but lower case when it means "they."

Now I'll show you one of the many reasons I love Chinese:

Wo shih = I am
Ni shih = you (singular) are
Ta shih = he/she/it is (no gender in Chinese, absolutely none!)

Wo-men shih = we are
Ni-men shih = you (plural) are
Ta-men shih = they are

No verb inflections either! Chinese has virtually no grammar. Just learn the vocabulary and string the words together in logical sequence. No endings. No present, past, future. No singular, plural (except the pronouns). No first person, second person, third person. No nominative, accusative (e.g. I/me, he/him). No endings. When all your words have only one syllable, that's to be expected! And Chinese has a perfectly logical way to distinguish between you singular and you plural. No formalities twist the words around. Of course the Chinese have plenty of ways to butter up an elder or a superior, but they do it by sticking some word like "honor" straightforwardly into the sentence, instead of butchering some other poor word into meaning something it does not.

Pollux
You brought up the confusing subject of irregular verbs in English. The problem is that there are two series. The first is what in German they call "weak verbs." In English that means that both the past tense and the past participle end in D. I love, I loved, I have loved. Some weak verbs are irregular but the pattern is at least barely visible, especially if you recognize T as just a modified D: I make, I made, I have made; I think, I thought, I have thought; I spend, I spent, I have spent; I hear, I heard, I have heard.

"Strong verbs" work differently. None of them is exactly "regular." The past tense is formed by changing the vowel, and the past participle is formed by changing the vowel again and adding the ending EN. I break, I broke, I have broken; I see, I saw, I have seen; I write, I wrote, I have written; I eat, I ate, I have eaten; I lie, I lay, I have lain. But a lot of strong participles have lost the N. I come, I came, I have come; I sing, I sang, I have sung; I sit, I sat, I have sat. You can recognize the most irregular strong verbs by the fact that their past and participles do not end with the suffix D or T, but they do have a vowel change.

And...
You speculated about the future of English and other languages. Civilization speeds the addition of new vocabulary as new technologies and philosophies are developed, but it slows the dispersion of one language into regional dialects, thence into mutually incomprehensible dialects, and finally into separate languages.

During the era of the Roman Empire, Classical Latin degraded slightly into Vulgar Latin, because literacy was rare and there were no electronic media to bring the Emperor's speech into every home. The grammar got simplified, some of the complexities of pronunciation were normalized, and a few colloquial words replaced their bookish equivalents. Nonetheless, in 400 CE a Legionnaire in Britannia spoke very nearly the same Vulgar Latin as his counterpart in Rome, and both could easily converse with the Emperor despite his Classical dialect, if such a thing were permitted. But when the empire disintegrated the Vulgar Latin of the provinces quickly morphed into regional dialects and just as quickly into separate languages.

Notably, the Franks, a Germanic tribe, superimposed their Germanic umlauted vowels (coeur, tu), their Germanic preference for the present perfect (I have gone) over the past tense (I went), and their distinct, gargled Germanic R, creating a French language that looks vaguely like Latin but sounds vaguely like German and has a grammar that is a vague hybrid of both. The Romanians did the same thing with a Slavic overlay. Latin "decem" for "ten" became "zeci," "et" for "and" was replaced by "si," and Romanian/Moldovan alone of all the Romance languages still declines nouns and pronouns in the nominative, genetive, dative, etc. cases.

The language of Iberia assimilated a caravan load of Arabic words and then split into Spanish, Portuguese, and Catalonian after the Moors left.

However, few languages have been through as many wringers as English. The Angle and Saxon colonists brought a language not much different from that which the Germanic people who stayed home were speaking. Then it immediately started absorbing Latin words that the people in unconquered Germany did not need to learn. The "Anglo-Saxons" would have ended up speaking a butchered version of Vulgar Latin like their Frankish cousins... except the Roman occupiers withdrew and left them speaking the "Anglisch" of Beowulf. ("Beowulf," the poem, that is, not Beowulf its hero, who was a Scandinavian and surely spoke Old Norse.)

Then in 1066 the French invaded and occupied Angle-Land, and for centuries the royalty and aristocracy spoke Middle French. The "English" had to learn many French words to get along, and soon their language had assimilated so many that even now, many educated foreigners say that a page of printed English looks more like French than its closest relative, Dutch. The French occupation never actually ended, they just assimilated the way the Mongol and Manchu conquerors disappeared inside China. The French influence was so pervasive that some of our basic bread-and-butter words like "question" and "very" are French, not German.

What we are happily left with is one of the richest languages in the world, with a vocabulary that rivals Chinese, about 75,000 words. Most languages get by with twenty or thirty thousand and many have even fewer. Our grammar has passed through so many mouths that despite its idiosyncracies like strong verbs, it is arguably the least complex of all Indo-European tongues. It has of necessity developed a word-building paradigm that accommodated all those borrowings from Latin, French, and Old Norse (a chapter in its evolution that I omitted for brevity). So we freely coin words like "television," a Latin-Greek hybrid; "reword," a French prefix stuck on an Anglo-Saxon noun, changing the whole thing into a verb; "concerning," a gerund pressed into service as a preposition; "user-friendly," two words efficiently crammed together in a manner that the Germans and Chinese thought they had patented; "radar," an abbreviation pronounced as a word; and "blog," an arbitrary shortening of two words into a single syllable.

Where will English be in 500 years? Look backward for a clue. We can still read Shakespeare's writing from 500 years ago. Not easily and not without giggling, but after a few pages its peculiarities start to make sense. What English has not done over the past 500 years is fragment into multiple daughter tongues or even dialects. The availability of education and the spread of literacy kept the regions from adopting too many divergent slang words or idioms, and the electronic age brought our voices into each other's homes so that even our pronunciation began to re-standardize. Compare the heavily accented Texas English of President Lyndon Johnson with the far more familiar-sounding speech of Texan G. W. Bush a mere forty years later.

What it has done is invent and adopt thousands of new words to go with the new arts, sciences, and technologies. Antiproton, laser, McPherson strut, inkjet printer, fax, digitize, robot, gung ho, perestroika, jihad, sandinista, boatlift, thermos, kleenex, aerobics, disco, hip-hop, reggae. Some of these will pass out of usage but most of them will not and they're all in the venerable O.E.D.

The next 500 years can go one of two ways. We can continue on our current path. The English-speaking world will continue to converge into a single dialect, with a wealth of new words added by the political, cultural, and scientific advances of the next five centuries. The people of the 26th Century will be able to read our books, not easily and not without giggling, but after a few pages its peculiarities will start to make sense.

Or the Third World War that the normally optimistic Gene Roddenberry throws in our face in every Star Trek series will happen, fought with weapons of mass destruction and setting civilization back a few hundred years. The forces that have been stabilizing our language and many others will weaken. There will be a family of languages descended from English. Perhaps Aussie, New England, Old England, Scottish, California Spanglish, Quebecois Franglais, etc. Or perhaps Martian, Earth, and Lunar dialects as the colonies lose touch with each other. Or perhaps English will be like Modern Greek, shrunken from a position of unrivaled leadership and a speaker base spanning multiple continents into a linguistic footnote spoken in England and a proud but tiny nation in what used to be the American Midwest, surrounded by new countries whose inhabitants speak Spanish, Chinese, Pan-Slavonic, and Arabic.

That's a tough call. I'll go with the optimistic version. It makes me feel better and it's not like I'll be around to see what really happens unless what's going on right now is the start of the unraveling.