III. Omission of some noun phrases in a sentence

Japanese people frequently omit those noun phrases which the speaker thinks the
hearer knows or can understand from the context or the situation.
Example
A : Shokudoo e ikimasu ka.
"Are you going to the cafeteria?"
B : Ee, ikimasu.
"Yes, I am."
A : Kaarin san wa.
"How about Karin san?"
B : Ikimasen.
"No, she is not."

In the example above, neither the first sentence nor the second sentence contains an actor who goes to the cafeteria. However, speaker A and speaker B know that the actor of the first sentence is anata"you"and that of the second sentence is watashi"I,"because it is quite probable that the speaker is asking about the hearer. In such a situation it is preferable to omit anata and watashi. Frequent use of anata makes speech unnatural to a Japanese ear. Even when"you"(anata) must be used, anata is avoided by a Japanese, and instead of anata the name of the person addressed is used.
This applies to any subjects which can be understood from the context.

Examples
1. Karin : Kinoo daigaku e kimashita ka.
"Did you come to the university yesterday?"
2. Lwin : Iie, kimasen deshita.
"No, I didn't."
3. Karin : Ruin san wa Tookyoo e ikimashita ka.
"Mr. Lwin, did you go to Tokyo?"
4. Lwin : Iie, ikimasen deshita. Kaarin san wa.
"No, I didn't. How about you, Karin san?"
5. Karin : Watashi mo ikimasen deshita.
"I didn't go either."