Has technology slowed or stopped the development of the core English language?
Solution 1:
Consider if the letter u being represented as v (as I pointed to earlier) — this would be a monumental change which would be unlikely to appear in the modern era, simply because of the number of standards (i.e. ASCII, Unicode, most all information exchange definitions, fonts, most programming language definitions, etc) which would be affected would be enormous.
I don’t think this is a particularly useful example for your hypothesis. If the English language needed to create another letter distinction such as the one that evolved between u and v, many of these pragmatic considerations might be avoidable if we simply borrowed another commonly-available glyph (from another language, a ligature or currency symbol, or whatever) instead of creating an entirely new letter shape. After all, that’s pretty similar to what happened with u and v: as you point out, the two shapes started off as orthographic variants of the same letter. In the 1800s, it would have been extremely expensive to add a new glyph to the metal type on printing presses — so when a distinction arose, they stuck to the glyphs everyone already had on hand.
Spelling reforms might be another “systematic change” in the English language. While it’s true that popular dictionaries have regularized formal spelling in the past couple centuries, that shift began before your hypothesized timing. Also, note that informal spelling has resisted such change; the orthographic shorthand often used in SMS and instant messaging represents one obvious example of the continuing evolution of accepted spelling in informal contexts.
You’ve indicated that adopting new vocabulary isn’t a systematic change, so widespread importation of words when English is forced to co-exist closely with another language doesn’t seem to be a relevant issue either. You also mentioned “structure words”, but those haven’t changed noticeably in the last couple hundred years, either. I’m pretty sure there haven’t been any major changes in the acceptability of different syntax structures in modern English, although I don’t have handy data for that one.
I’m unsure how to get solid data about the frequency of significant morphological and grammatical changes on this 100–200 year timescale, so I can’t address those aspects.
Solution 2:
To answer the original question: No, technology has not slowed or stopped the development of the English language. This is partly because language is always developing, but also because it is difficult to define what you might mean by "slowed or stopped development".
However, technology has proven effects on how English has developed.
It is a historical fact that the advent of widespread printing encouraged fixed and consistent spelling. Unfortunately, it happened just as English was undergoing a wave of spelling changes, so many words are stuck. This was not helped by numerous scholars "correcting" the spelling of words, often based on perceived etymology.
Likewise, it is also true that the loss of the letters thorn (þ) and eth (ð) were finalised with the popularity of movable type, because movable type was popularised in Germany and German doesn't have those letters.
A more modern example is the advent of trans-Atlantic communication. Scholars have argued that North American English was on the road to diverging from British English, until this was slowed by the advent of radio communication. It could be argued that even today, this still helps keep the major dialects of English mutually intelligible, whilst at the same time encouraging faster development by borrowing from more places than ever.
Solution 3:
I don't think that technology has reduced the rate at which language develops - but it has homogenized it somewhat (although, there are still regional variations - British-English and US-English being the obvious). In fact, the homogenization started some time ago with the introduction of the printing press and standardised dictionaries.
We are still gaining new words, losing old ones, replacing the meanings of words, and so on - and I'm pretty sure even grammar is evolving.
Solution 4:
It does make sense. Fixation and normalization of the written word are the result of printing becoming widespread and cheap. I don’t think it’s a matter of standardization becoming important as much as it is a matter of drift becoming more expensive and just less likely. The variation of spelling in English history you note is probably the most obvious and measurable judge. How many ways was the Bard’s name spelt at one point? I’ll bet some great statistics could be cooked up. I think Google even has an API/lab for searching historical documents now… though the URL/name eludes me.
In spoken language the United States was on its way to pretty divergent dialects a hundred years ago. I’d argue that radio and then television halted this and even began to reverse it. The kids born in Brunswick today will have no trouble conversing with those born in Beaumont when they land in SoCal; they are all raised on audible media mostly comprising a narrow band of neutral Canadian/Central-US accents.
This and the print issue are the same; distribution and access versus geography and lack of example. In evolutionary terms, mutations are tremendously reduced. The speed of evolution is slowed.
Solution 5:
It does make some sense that computers and the Internet stifle change in English. However, in the opposite direction, there are some changes that are due to modern technology. While I can't think of any in English, one in Romanian is the now-common use of cedillas under the letters s and t where commas used to be used: computer systems for a long time only supported cedillas, so those became common. (Unicode now supports both, so perhaps the pendulum will swing back.)