Being a user (and a passive reader) of several languages, I’ve noticed that English words tend to be shorter on average than words in other languages. I believe the reason for that is twofold:
English is a fairly isolating language
Being “isolating” is a linguistic term that means, simply put, that the number of “pieces of information” per word is very low. To understand what a “piece of information is”, let’s take a look at the word “unlawful”. The word “law” carries just one piece of information, “lawful” carries two (“by law”), “unlawful” carries three (“not by law”). English lacks the following “non-isolating” constructions commonly found in other languages:
Case endings. Slavic languages, for instance, have an elaborate system of case endings, thanks to which it is often possible to add an ending to a noun instead of using a preposition. For example, “a tent” would be stan in Czech (there are no articles in Czech, so “a” is implied), “to a tent” would be stanu, and “by a tent” would be stanem. As you can see, we use three short words in English for what would be just one longer word in Czech.
Verb endings. A similar trend can be observed in verbs. “To speak” is hablar in Spanish and mluvit in Czech; the -r in Spanish and -t in Czech already indicates it is an infinitive. In English, we have to use the short word “to” to make this clear. If we want to say “I will speak” in Spanish, we can say simply hablaré—the -aré ending already carries the necessary information about the subject and the tense. Similarly, in Czech, we can say promluvím; “pro-” puts it in the future and “-ím” indicates the subject is “I”. In summary, we have to use three short words in English in a place where we would use just one longer word in Spanish or Czech.
Phrasal verbs. There are important differences in the way new “meanings” are formed from the words we already have. In English, there are a lot of phrasal verbs like “go off”, “look after”, “show up”, etc., and not so many verbs formed using a prefix (e.g. “overlook”, “upset”). This is not the case in other European languages where “phrasal verbs” are usually formed by adding a prefix, so the three mentioned would be something like “offgo”, “afterlook”, and “upshow” (of course, there’s often little logic in these, so the literal translation of the two parts into another language would almost never work, but I hope it illustrates the general idea).
German is actually somewhere in between English and other languages in that respect. In certain positions, the “prefix” is a separate word, in others, it isn’t. For example ich nehme an means “I suppose” (literally “I take on”) and ich muss annehmen means “I must suppose” (literally “I must ontake”). However, considering we can stick nouns together in German almost freely, this little feature doesn’t really matter in terms of the overall impression of word length.
Compound words. And so we come to the last important difference between English and German. There are a relatively modest number of compound words in English, like ear⋅ring, foot⋅print, or sun⋅light. Or is it?
In fact, the difference between English and German in terms of long compound nouns is mostly typographical. English speakers just like to write compound words separately; we write “university student” instead of “universitystudent” (Hochschulstudent), “house cleaning” instead of “housecleaning” (Wohnungsreinigung), and “back pain” instead of “backpain” (Rückenschmerz). Call the first word in the pair what you will (you may say it acts as an adjective or that it is simply a noun used as a modifier), but the structure is completely the same as in German; Germans just don’t write the spaces in between.
English is very open to abbreviations
Users of English have a tendency to shorten words. While we may cringe at the word “cuz” some people use to abbreviate “because”, the tendency to treat abbreviations as full-fledged words has been there for centuries. To name just a few well established one:
- refrigerator (spelled fridge)
You can certainly think of dozens of similar examples, many of which may be considered colloquial now but will probably become common usage after a few decades. This tendency is by far not as strong in most other languages, so this process leads yet again to shorter average word length in English.