The Japanese purehabu jūtaku (プレハブ住宅, prefabricated housing) industry is massive and allows quality homes to be built piece by piece in a factory and then assembled on site. The University of Virginia School of Architecture has gone as far as to call the Japanese modular home-building industry “clearly the most sophisticated in the world.”
I can’t say whether Japanese is the most sophisticated language in the world, but at times it does feel quite modular. It’s easy to substitute words in and out of phrases to adjust the meaning of a sentence thanks to the ease with which the language modifies nouns. In particular, words that describe timing and conditions make it easy for speakers to be incredibly precise using very few words.
First we should review how Japanese modifies words. It’s actually really simple: Adjectives and verbs attach straight onto nouns. This makes it easy to turn a sentence like Tenki ga yoi (天気が良い, “The weather is good”) into yoi tenki (良い天気, good weather). This phrase can then easily be used as the subject of a sentence: Yoi tenki ga suki (良い天気が好き, “I like good weather”).
The same is true with verbs. Take Inu ga nete iru (犬が寝ている, “The dog is sleeping”) and turn it into nete iru inu (寝ている犬, sleeping dog). Then make a sentence: Nete iru inu o okosanai hō ga ii (寝ている犬を起こさないほうがいい, “It’s best not to wake sleeping dogs”), a translation of the famous proverb — perhaps a little too chokuyaku (直訳, directly translated).
You can also straight-up attach sentences to other nouns. For example, if you’re at a party and trying to tally the folks that ordered beer, you could say the following with an inquisitive rise in tone at the end of the phrase: Biiru o chūmon shita hito? (ビールを注文した人？, “Those who ordered beer?”).
Now, on to the modularity. The simplest of the modular words I’m thinking of is toki (時), the Japanese word for “time.” Toki is a total party animal and is up for almost anything: Just modify toki and suddenly it’s time for that thing.
Neru toki (寝る時), time for bed! Benkyō suru toki (勉強する時), time to study! Chotto kyūkei suru toki (ちょっと 休憩する時), time for a little break! Feel free to get longer and more specific: biiru ga nakunatte kawari ni happōshu o nonde shimatta toki (ビールがなくなってかわりに発泡酒を飲んでしまった時), meaning “the time when the beer ran out and I unfortunately drank happōshu (発泡酒, a low-malt beer-like alternative)!
Of course, these are all unfinished phrases awaiting a predicate to complete them. Leave the modifier in the present tense to speak in generalizations: Densha ni noru toki, ashimoto ni go-chūi kudasai (電車に乗る時、足下にご注意ください, “Watch your step when boarding trains”). Or turn it into past tense to talk about a specific instance: Densha ni notta toki, saifu o motte ita kedo, orita toki nakatta (電車に 乗った時、財布を持っていたけど、降りた時なかった, “I had my wallet when I got on the train, but when I got off it was gone”). Change toki to shunkan (瞬間, instant/precise moment) to emphasize the fleetingness of the moment: Densha ni notta shunkan ni hakike ga shite kimochi waruku natta (電車に乗った瞬間に吐き気がして気持ち悪くなった, “The instant I got on the train I got nauseous and felt terrible”).
Sub in the word aida (間) for toki to express a duration of time: Densha ni notte iru aida, zutto inemuri shite ita (電車に乗った間、ずっと居眠りしていた, “I nodded off the whole time I was on the train”).
Getting even more precise involves calling into action the word tokoro (ところ), which my translation professor used to call “time-space.” Tokoro often translates as “place,” as in watashi no tokoro (私のところ, my place), but when modified by a verb, it is very useful for establishing precise moments in the “time-space continuum.” Just adjust the verb tense to change the moment.
Densha ni noru tokoro (電車に乗るところ) —present tense, in other words —refers to the moment immediately before you get on the train. Change this to the present progressive densha ni notte iru tokoro (電車に乗っているところ) and you are referring to the precise moment you are stepping on the train. Past tense, or densha ni notta tokoro (電車に乗ったところ), is the moment just after you boarded.
This is an especially useful construction when you are trying to explain that you are preoccupied. If you receive a phone call in the middle of dinner, you can tell the caller, Jitsu wa ima bangohan o tabete iru tokoro desu ga (実は今晩ご飯を食べているところですが, “Actually, I’m eating dinner right now, but . . .”), which should imply on its own that you’re not free to talk.
And last but not least, baai (場合) is a word that means “case/condition” and is useful when discussing potentialities. Consider it a way to say “if X,” where X is the phrase/sentence that modifies baai: Densha de kuru baai, eki ni tsuitara denwa shite kudasai. Mukae ni iku kara (電車で来る場合、駅に着いたら電話して ください。 迎えに行くから, “If you come by train, call me when you get to the station. I’ll go out to meet you there”).
Once you master the ability to rearrange these modular modified words, you should find that your Japanese quickly becomes more efficient.