Overall, I find Japanese to be very subtle, and complex ("recondite" is probably the right word / no disrespect intended). The more I study (and therefore the more I find that I don't know), it's nice to have a small epiphany from time to time. if anything just to keep spirits up.
These are pseudo-random things I learned along the way during my study of Japanese. They're in no particular order (of "potential interesting-ness nor inherent insight/complexity").
"deshita" (でした) is what's known in English as a "verb auxiliary" in that it's used to modify the meaning or intent of a verb. In this case, it puts a verb in the past.
Now, while that's all fine, it's not what's interesting to me. What's interesting (おもしろい) to me is it's derivation, which I'll endeavor to explain now.
The root verb (of deshita) is "desu" (です), which means "to be". Before this will make sense, it will be helpful to explain the very basic rules for conjugating Type 1 Japanese verbs.
Japanese verbs are decently regular in their conjugation rules. They follow the standard order of vowels in Japanese to form other meanings of a given verb, e.g.:
Verbs ending in "u" follow a-i-u-e-o (あ-い-う-え-お).
Verbs ending in "ku" follow ka-ki-ku-ke-ko (か-き-く-け-こ).
Verbs ending in "su" follow sa-shi-su-se-so (さ-し-す-せ-そ).
(and similar for other last vowels/consonants).
(Note: it's always the 3rd vowel/consonant, as you'll see below, the dictionary form of each verb is 3rd in the conjugation table).
Consider the verb "kau" (かう) "to buy. Because it ends in "u", it's conjugated by following the standard order of "a-i-u-e-o" (あ-い-う-え-お). Here's the conjugation table (the vowels are annotated like so (あ) to highlight their order:
The more astute among you will note that "a" (あ) is written as "wa" (わ). Apparently, in old-skool Japanese, "a" was always proceeded by "w", and this is one artifact of that rule that still applies (in the Negative conjugating of a verb, where you might be tempted to use "a", use "wa" instead).
The other set of conjugations are te-, ta-, tara-, and tari-. For the sake of simplicity, we take the 2nd (Conjunctive) root and add those suffixes, with some simple, regular variations. E.g: here's "kau" (かう) finished off:
Now: back to deshita. We know that "desu" is an auxiliary, and as such, it's conjugation is a bit irregular, so I'll provide it's tables and then [hopefully] point out the "voila" moment (where it all makes sense)..
And the te-, ta-, tara-, and tari- forms:
In case it's not obvious: the ta- form of "desu" uses a conjunctive stem of "deshi" because it uses the 2nd consonant in the set (さしすせそ) plus the root (で) to began with "でし", and then to get the past tense, you just add "た" and voila!: you end up with "でした" (deshita), aka "was".
Explained another way: "desu" (です) (3rd form / す) has a conjugation stem of "deshi" (でし) (2nd form / し) and therefore it's past tense is just "deshita" (でした).
This one is much easier to explain. When I was first learning Japanese, I learned three common te- (て-) verb variations:
E.g.: the verb "to eat" is "tabemasu" (まべます), and it's te- form is "tabete" (たべて). To say "Please eat", "May I eat?" and "I am eating" you just add the above to the te- form like so:
This all seemed complicated, and intimidating when I was first learning it, but the funny part about "May I..." is that I later learned it translates to "good, is, yes?"
"Good" (いい), "is" (です), "yes" (か)?
One of the most useful words in the Japanese language is "sumimasen" (すみません), which translates to "pardon me" / "excuse me" / "apologies for interrupting you". You'll need this one to eat at a restaurant in Tokyo because it's how you summon your waiter (it's also how you lead when you're about to bug someone for directions or information).
The verb "sumu" (すむ) in Japanese has two meanings:
Going back to our verb conjugations, let's look at the conjugation for sumu:
The key form is the "conjunctive" which has three general forms:
Recognize "sumimasen"? It's that most useful word from Japanese. The one you use to interrupt your waiter, or to ask someone for directions.
Apparently, interrupting someone incurs a sort of temporary debt, which will [of course] be un-repaid... and this appears to be the historical reference behind why that word means what it does.
すみません ("sumimasen") : "I apologize for interrupting you and have now incurred a debt, which has not been paid, and therefore we are not finished."
(I'll admit that for the longest time I thought it meant "Don't live / don't reside", as in: "You were living contentedly before I interrupted you, and now you're not (because I'm bugging you), and therefore sumimasen".
This one is wicked simple. The word "onegaishimasu" (おねがいします) means "please". It's an incredibly common word in Japanese.
As it turns out, the word "onegai" (おねがい) is a noun that means "favor" and "shimasu" (します) is the ubiquotous word for "to do", and so when you think you're saying "please", you're saying "do a favor".
I have to admit this one is my favorite. It took a little for me to dig into this one and try to make sense of it's origin, and I think I can explain it fairly succinctly.
To say "I must ____" in Japanese, as in "I must read", it's quite a heavy lift: よみ なければ なりません ("yomi nakereba narimasen").
I can explain.
Let's start with the verb conjugation table for the verb "yomu" (to read):
Now, the key is that the 1st form ("I don't read") can actully be itself conjugated using the same rules as other verbs. In this case, "yomanai" becomes "yomanaku", which is the 3rd form for our next conjugation.
(Why does it become "yomanaku"? That'a a good question and slightly beyond the scope of what I'm trying to explain. "ku" (く) is used as a conjugation suffix when converting nouns to adjectives and adjectives to adverbs)
Okay. So. Putting that 1st form of that conjugation as the 3rd form of a new conjugation table gets you this:
Note the 4th conditional: "If I don't read" ... that's the 1st half of "[yoma]nakereba narimasen".
The back half is much easier .. "narimasen" comes from the verb "naru" (to become). Here's it's conjugation table:
The key form is the "conjunctive" (aka: "the masu form") which has three general variations:
There's our "narimasen"... it's the back half of this recondite expression that we'll see translates to simply "must".
So let's put it all together: if "yomakereba" is "if I don't read", and "narimasen" is "I will not become", then combined they [literally] translate to "if I don't read I will not become", which colloquially translates in English to "I must [read]".
This one is just a funny one I stumbled upon accidentally.
The verb "we will do our best is" is がんばろ (ga.n.ba.ro).
E.g: これから いっしょに がんばろ
"From now on, we will do our best".
However, if you misspell "ganbaro" and make it "gandaro" (which is only one character difference:( ば --> だ), it becomes:
E.g: これから いっしょに がんだろ
"From now on, let's get cancer together".
Not sure what the take-away is here. Perhaps: がんばって ください！.