Plurals are used only for people and animals in Japanese, and are optional even for them. Especially in conversation usually Japanese speakers don’t bother to pluralize nouns.

  • 家で子供 (達) が私を待っている -> My kids are waiting for me at home
  • 沢山のファン (達) が会場に押しかけた -> Throngs of fans flocked to the concert hall

“人” as “other people”, “people in general” and/or nonspecific people is always singular

  • 人とはそういうものだ -> That’s how people are
  • 彼は人の言うことは気にしない -> He doesn’t care what people say
  • 通りに人が沢山集まっている -> There are many people gathered on the street
  • あの辺は人が多過ぎて行くのが嫌になる -> There are too many people in that area, it is too crowded, that I don’t like to go there

Compare the below with the above:

  • ああいう人達とは付き合えない -> I can’t get along with people like that
  • やる気のある人達が集まった -> The motivated people got together

Plurals are not used for concept or abstract groups of people and animals:

  • 私は子供が三人いる -> I have three as child. I have three children (❌”子供達が三人いる”)
  • 彼女は子供が好きだ -> She likes children (whoever they are) (❌ “子供達が好きだ”)
  • 私は犬が大好きだ -> I love dogs, I love the dog (❌ “犬達が好きだ”)
  • 彼は競走馬を育てている -> He raises racing horses
  • 従業員以外立入禁止 -> No Entry. Employees Only

Plurals are not used for inanimate things.

  • 日本には火山が沢山ある -> There are many volcanos in Japan
  • 彼は沢山のCDを持っている -> He has many CD’s
  • 林檎を幾つか買った -> I bought some apples
  • 私は絵を集めている -> I collect paintings

[何(なん)+counting suffixes] are often used to express “many of such and such”:

  • この辺には豪邸が何軒もある -> There are many mansions in this area
  • 彼はCDを何枚も持っている -> He has numerous CD’s
  • 彼女は猫を何匹も飼っている -> She has many cats