This is his book, (and) not mine.
これは彼の本で，私のではない
This is his very own room.
これは彼専用の部屋だ
This is in reply to yours of the 15th inst.
((やや古))本月１５日付の貴簡にご返答申しあげます
This is just about the worst article I have ever read.
今まで読んだ中でほぼ最悪の論文［記事］だ
This is just between you and me [ourselves].
ここだけの話だよ
This is just luck.
運がよかっただけさ
This is just one phase of the problem.
これは問題の一面にすぎない
This is just [only] talk rather than a meaningful statement of intent.
これは意図をもった発言ではなくただの戯れ言だ
This is merely an outline of a possible procedure.
これは単に可能な処置の概略にすぎない
This is my first visit to New York.
ニューヨークはこれが初めてです
