Logic behind grammar patterns


One of my current biggest challenges in learning Japanese sentence patterns is
knowing which verb forms to use when linking to set phrases.

The largest classes of verb forms I've seen that are used to link verbs to
other structures are 連用形｛れんようけい｝ (stem form), テ形｛けい｝ (te form), and 普通形｛ふつうけい｝
(plain form). Here are some examples of grammar patterns from each category.

**連用形 (stem form)**

  * 連用形＋はじめる（例：今週｛こんしゅう｝、日本語｛にほんご｝を勉強｛べんきょう｝ **し** はじめました。）
  * 連用形＋方｛かた｝（例：この漢字｛かんじ｝の **書｛か｝き** 方はとても簡単｛かんたん｝ですね。）
  * 連用形＋たい（例：今晩｛こんばん｝、天｛てん｝ぷらを **食｛た｝べ** たいです。）

**テ形 (te form)**

  * テ形＋いく（例：ちょうちょうは **飛｛と｝んで** いた）
  * テ形＋ください（例： **聞｛き｝いて** ください）
  * テ形＋ほしい（例：レストランに一緒｛いっしょ｝に **行｛い｝って** ほしいです）

**普通形 (plain form)**

  * 普通形＋かもしれません（例：東京｛とうきょう｝に **行｛い｝く** かもしれません）
  * 普通形＋ようになる（例：練習｛れんしゅう｝したから、今｛いま｝漢字を **書｛か｝ける** ようになりました。）
  * 普通形＋ところ（例：彼｛かれ｝と犬｛いぬ｝は公園｛こうえん｝から **来｛く｝る** ところです。）

(Feel free to correct my grammar in any of these examples too if there are any
errors as I'm still learning!)

Anyhow, if you were given an arbitrary grammar structure, such as `＋はじめる`,
`＋ください`, `＋かもしれません` without knowledge of which verb form should preceede,
would there be any logic in how to retroactively figure out (or at least have
a good guess) as to which verb form should come before?




I will be interested to see if someone can produce a good, comprehensive
answer to this question. I only have a partial answer; as an advanced learner
but non-native speaker, the reasons for distinctions between constructions
that use テ形 and those that use 連用形 seem pretty arbitrary, though I'm sure
there are historical or etymological reasons.

That said, the examples from your 普通形 section are much easier to explain. I'm
not going to touch on the semantics here because that doesn't appear to be
what you're asking about, just how these phrases behave grammatically.

You can think of `かもしれない` as

> か＋も＋知れない

(see
[here](https://kotobank.jp/word/%E3%81%8B%E3%82%82%E7%9F%A5%E3%82%8C%E3%81%AA%E3%81%84-466938))
and it's not only usable with verbs. Grammatically this behaves the same way
any other verb taking embedded questions ending in `か` does; you can say
`彼はばかかもしれない` or conjugate the `知れない` to make it more formal like `そうかもしれません`.

`ようになる` is :

> よう＋に＋なる

There are a large number of other possible constructions involving `よう`
followed by various particles and verbs. However, the important thing is that
grammatically both `よう` and `ところ` behave like nouns - when you use plain form
verbs with them, it's only because relative clauses that qualify nouns are in
plain form. It's the same reason that in`犬を怖がる猫`, `怖がる` is in plain form
(because it's qualifying the noun `猫`).

