Translation:He does not have children.
Is there a reason that "He does not have a child" is an unacceptable translation?
In most Asian languages all nouns can be equally as singlar as they are plural. The only exceptions are when counting words and numbers are used as pronouns
William Shakespeare Quote
William Shakespeare “He has no children.—All my pretty ones? Did you say all?—O Hell-kite!—All? What, all my pretty chickens, and their dam, At one fell swoop?”
What is the difference between 孩子, 孩, and 子? According to my dictionary they all mean child.
I'm not a native, and I can't say this applies in Chinese as much as Japanese, but essentially 子 means child as in 猫子 (kitten), 狗子 (puppy), and when written alone it can technically mean mouse when speaking about the zodiac signs. 孩 however, only applies to human children, especially babies and young infants. When combined, it's the Chinese compound for someone's child (ren), probably the same way 弟弟 and 妹妹 are 2 characters just because before writing, the word was 2 syllables. I'm not fluent though so please don't take this as the ultimate truth, just as an educated guess from years of studying 漢字
You can technically say all 3, but in most cases 孩子 is the most typical and formal
It is not proper in English. "Has not" is used for actions in the past. Here, you should use "has no" or "doesn't have" because it refers to possession. So your sentence should be "he has no child" or "he doesn't have a child" instead.
He doesn't have kids This language tab is so tough especially in English writing . . .