A halfway alternative to an international language

One other interesting idea for improving communication among languages besides (or even along with) the establishment of an international language could be a bit of tweaking to languages themselves, in a way that native speakers don't find to be overly repulsive. This tweaking would largely involve the restoration of vocabulary that speakers of other languages have an easy time understanding, and it's reasonable to expect that a good look into the vocabulary of major European languages should turn up at least a few hundred of these words.

English has a few good examples, such as the words overmorrow and ereyesterday. Overmorrow = the day after tomorrow, ereyesterday = the day before yesterday. These words are good examples because:

1) They were previously used in English,
2) They aren't particularly strange even to modern speakers (morrow is still known as a separate word and ere isn't too unfamiliar either),
3) They are cognate with other Germanic languages (German übermorgen and Dutch overmorgen, plus Dutch eergisteren for ereyesterday),
4) The existing English words are far too long anyway. The day after tomorrow is 21 keystrokes and 7 syllables vs. 10 keystrokes and 4 syllables for overmorrow, while The day before yesterday is 24 keystrokes and 7 syllables vs. 12 keystrokes and 4 syllables for ereyesterday.

The most important prerequisite for this would simply be the possibility of them being used again, or in other words native speakers not hating the restored terms, because it's simply impossible for a word to be restored to currency when people simply can't stand the idea of using it.

On the other hand, simply restoring Germanic (and maybe Latin words on the Romance side) terms alone wouldn't be permissible if there was no discernible benefit. The French Revolution could be called The French Overthrowing in English, but not only could this make the word revolution less understandable to future English speakers, but other English words (revolve) would still be there. Words that are easy to understand and also easily derived (revolve/revolver/revolution) would not be touched.

Semantic shifts would also be left untouched. English fowl now means a certain type of bird, while beam doesn't refer to a tree anymore. Plus, tree is tre in Norwegian so it isn't unique to English either.

Some other words might be proposed as literary alternatives, such as welkin for clouds or the heavens. Welkin appears often in Shakespeare, and is also cognate with Dutch wolk and German Wolke. These words would be proposed though with the understanding that modern users simply might not be interested, whereas overmorrow and ereyesterday are actually more efficient alternatives to the current unwieldy terms.

Doing this with each language would still only result in a tiny bit more mutual comprehension, but the debate alone on finding some easy ways to achieve a more common vocabulary without having to make any major changes could be a good one, and may lead to the discussion of IALs at the same time.

Any French/Spanish/etc. users that have a few good examples there as well? I can think of a few myself but have no sense for what average people would welcome or despise based on a gut feeling alone.

Edit: here's an interesting thread debating the merits of reviving thou. One definite benefit to a revival of thou would be translation, where often works translated into English need to find inventive ways to express the difference between the formal and familiar second person pronoun, a distinction present in just about every European language.