Are the 彼の and あの in the examples necessary or optional?


Are the 彼の and あの in the examples necessary or optional?

**Example 1:**

> 彼は彼女と別れた。"彼の"判断は正しいね。

**Example 2:**

> 新しいパソコンを買ったね。"あの"パソコンは画質がいい？




In both examples, possessives cannot be omitted.

First, in both cases your second sentences are not very natural. Some possible
alternatives are:

  * 1a. (それは)正しい/賢明な判断だね.
  * 1b. (彼の判断は)賢明だね.
  * 2a. (そのパソコンの/は)画質はいい？

As you can see from 2a, it is sometimes possible to omit possessive phrases.
Easier examples:

  * スマホが壊れた
  * 彼女がパソコンが壊れたと電話してきた
  * 年末にPCを買った。性能はいいが、値段は高かった.

The first one means _**my** smartphone_, the second _**her** PC_, and the
third _**its** specs/price_.

Another way to look at the examples would be that you can omit the topic when
it is clear. That is, _(Speaking of his decision to end the relationship with
her), it is wise_ ; _(As for the PC you bought), is the display good?_ , etc.

