As languages go, English, especially the American dialect, is something of a hodgepodge. Unlike French, for example, there is no ministry tasked with the job of keeping the language pure of foreign influence. While some buckaroos might kvetch about this deficit, in a way, I believe that it's an advantage because it allows the language to change and allows its speakers to grok new concepts rather quickly. There is, however, one concept that the English language doesn't handle very well: time travel.
Although major strides have been made in the last few decades, the majority of the problems with time travel and the English language remain. Here are two examples of progress.
Jack L. Chalker coined the terms nightsider and nightsided in his novel Downtiming the Night Side. For those of you unfamiliar with those terms, a nightsider is a time traveler who, through a change in the time line, has no origin. Nightsided refers to becoming a nightsider through the actions of themselves or another. For instance, stop yourself from travelling into the past by destroying your time machine before you departure, and you've just nightsided yourself.
In his 1632 series, Eric Flint solves the problem of how to differentiate between the people of Grantville West Virginia from the year 1999 from the people of Europe of 1631. Respectively, the terms used are uptimers and downtimers, which is quite a useful distinction, provided that there are only two groups. Add a third group, and the result would be something along the lines of downtimers, midtimers, and uptimers, which is workable. However, anything beyond three groups would become increasingly complex to the point of being unworkable.
In spite of advances like the aforementioned, problems with the English language where time travel is concerned still exist. Consider for a moment that at the age of 30 you are thrown back in time to 100 years before your birth and then asked your date of birth. Not wanting to lie, should you reply that you were born on a specific date or that you will be born on a specific date? With the former response, you're using your frame of reference, forcing the listener to adjust; with the latter response, you're accommodating the listener, forcing yourself to adjust.
Another issue that English would have to deal with is the subject of future events. First, assume that time is immutable so that events cannot be altered; this results in the accommodation issue previously described. However, if events are not immutable and can be changed, then things begin to get really hairy. The time traveler's unique knowledge would become increasingly useless and were and will be would become intermixed with might and maybe. Without an agreed upon frame of reference, it would be impossible to convey any information of possible future events.
The problems of language conveyed here only scratch the surface of some of the issues that could arise in English from time travel. Since English is a rather dynamic language and we've got time before a time machine is invented (although not as much as we'll have after a time machine is invented), I'm interested in suggestions on how to get past these issues.