Page 66 - Makino,Tsutusi.DictionaryOfIntermediateJGrammar

SPECIAL TOPICS IN INTERMEDIATE JAPANESE GRAMMAR
(35) Sentence- Pre-verbal Verbal
initial element
element

NP-Prt.

Conj.
Adverbial
{V/Adj/NP[s] + Cop.](+Aux)(+Prt.)
Topic Adverbial
[SI
...

[S]: Clause
NP[s]: NP containing [S]
Adv[s]: Adverbial containing [S]
That is, a sentence which contains at least one of the elements containing [S]
in (35) is a complex sentence.
F. Missing Elements
Such sentence elements as illustrated in (35) are not always explicitly present.
In fact, sentence element ellipsis is very common in Japanese. When clauses
have shared elements (e.g., subjects), the shared element is usually ellipted in
the second (and following) clause(s). Sentence elements are also dropped
when they have been mentioned in a previous sentence, are contextually
known, or situationally known, or when they indicate a generic agent such as
"they" and "we." (36) provides examples.

(36) a. Shared by two clauses:
8%3/v;?lr-?D~ 2 9~b1-C 6 2 91 [%&Kl&;ihb1~7;
3 blo
(Even if Mr. Sawada asks about that, please do not tell [him]
[about it].)
b. Mentioned in a previous sentence: