1. Noun.
Japanese nouns has only one form, which is not change to indicate number, gender, or the role that the noun plays within the sentence. The same form is used under all circumstances.
猫 neko = a cat, the cat, the cats, cats
電車 densha = a train, the train, the trains, trains.
傘 kasa = an umbrella, the umbrella, the umbrellas, umbrellas.
This will probably seem very imprecise for English speaker, and you may wonder how we are going to express our thought. We can used as we do with English words as sheep, fish, quail, or deer. In most cases, the number of things that we are talking about will be clear from context. Where it is necessary to be specific, we can always use numbers or words indicating quantity.
たくさんの自動車 takusan no jido-sha : many automobiles.
2. Personal Pronoun.
In modern colloquial Japanese the personal pronouns are usually omitted if the meaning of the sentence is clear without them.
ご機嫌（きげん）いかがですか? gokigen ikaga desuka : How are you?
元気です。genki desu : I am fine.
When it is necessary to express a pronouns, either for emphasis or clearness, use these words,
私 watashi : I, me 私たち watashi-tachi : we, us
あなた anata : you (single) あなたたち : anata-tachi : you (plural)
彼 kare : he, him 彼ら karera : they, them
彼女 kanojyo : she, her 彼女たち kanojyo-tachi : they, them
In addition to these normal-polite forms, Japanese is very rich in other words that convey great variety of shades of familiarity, or politeness, and formality. Most of these form are beyond the scope of manual.
For example, I = 僕 boku 私 watash 俺 ore 自分 jibun 拙者 seltusha 私め watakushi-me 我輩 wagahai 小生 shousei 朕 tin.
Like noun, pronouns do not change their forms according to their use in sentence.
私の watashi no : my 私たちの watashi-tachi no : our
あなたの anata no : your (single) あなたたちの : anata-tachi no : your (plural)
彼の kare no : his 彼らの karera no : their
彼女の kanojyo no : her 彼女たちの kanojyo-tachi no : their
The impersonal pronoun ‘it’, in such expression as, “It is raining”, “It’s Sunday” is not translated into Japanese.