Japanese conversation has the added benefit of making it difficult to eavesdrop on peoples’ conversations and understand immediately what they’re talking about. Japanese people can listen to a conversation, but without the background knowledge, even they might struggle to work out what it’s about if the speakers are being careful not to mention the subject of their conversation. In English, it’s more difficult to leave out the grammatical subject and still make yourself understood. Eavesdropping is therefore easier to do on English speakers than on Japanese!
One of the first things Japanese learners encounter are the particles WA （は）and GA（が） — closely followed by WO （を）DE （で）, E （へ）, NI（に）, TO （と）etc.
Most learners, however, will begin by practicing the basic greetings for “Good morning”, “Good afternoon”, “Good evening” and “Good night”, in addition to some other common expressions such as “Thank you”, “Please”, “Goodbye” and so on. Of these, only the greetings “Good afternoon” （こんにちは）and “Good evening” （こんばんは） contain the particle WA because they are shortened versions of what were originally longer sentences. Therefore, the importance of WA as a subject-marker will not immediately be clear. This particle’s role begins to make itself known when you start to form full sentences.
WA particle （は）
The basic Japanese word order is Subject — Object — Verb, compared with Subject — Verb — Object in English. Therefore, the Japanese equivalent of “My name is…” can be expressed in full as: [Watashi no namae WA (insert name) desu. ] (My name — insert name — is). In Japanese script, this would be: 私の (my) 名前 (name) は (WA) [insert name] です (is) 。 If we replace WA with “AS FOR” in English (as Japanese often do when translating into English), this should give you an idea of its function. The Japanese for “My name is” can be represented in English more literally with: (“AS FOR my name, it is name”. )
While the English can be contracted to “My name’s…” or substituted with “I am…” or “I’m…,” it isn’t natural or even grammatically possible to omit the subject “My name” or “I” in such a sentence. However, in Japanese, with its speakers’ non-verbal style of communication, it is perfectly natural to leave out the subject. In fact, omitting the subject is actually required if you don’t want your Japanese to grate on the ear of the average Japanese native.
The structure of the language, with its use of particle markers, thus makes leaving out the subject quite effortless. Take, for example, the above-mentioned phrase for “My name is….” When Japanese speakers introduce themselves, they will usually omit “Watashi no namae WA (My name) “completely and just say: “[name] desu” after the equivalent expression to “Nice to meet you. “which is “Hajimemashite”. The omission of the subject is not limited to simple sentence structures but takes place throughout a conversation or within a text, whether the situation is formal or informal. Indeed, in formal or business self-introductions, the Japanese for “My name…” (Watashi no namae) is still omitted, but the verb “desu” is replaced with “tomoushimasu”（と申します） — a class of speech pattern termed “humble”. You’ll find out about “humble” and “honorific” speech patterns if you take your Japanese from elementary to a more advanced level.
Anyway, the structure of English is such that the important information usually comes near the beginning, whereas in Japanese, the important information is often near the end of the sentence. Therefore, partly due to these syntactic differences, and partly due to the aforementioned verbal and nonverbal communicative/cultural differences, the onus in English is often on the speaker to avoid all possible ambiguities, but in Japanese, the onus is more on the listener to extract the meaning from the context. In Japanese, you not only have to listen to the speaker, but demonstrate that you’re listening attentively by making well-timed interjections such as “mm” or “Oh, really?” * at appropriate intervals far more often than in English and wait until the speaker has finished their sentence before replying, offering your opinion or making a comment.
If you fail to do any of these, the speaker will likely grow uncomfortable quite quickly and perhaps get irritated or worry that you haven’t understood them correctly. This is different to English where speakers are able to interrupt quite quickly without waiting until the end of the sentence. In English, most of the important information is relayed earlier than in a typical Japanese sentence. The listener will, therefore, not annoy the speaker if he or she interjects with comments or questions before they have finished their sentence. All within reason of course!