Why do we say ‘I have "a" husband (wife)?

Though it may sound a very primitive question to native English speakers, the use of ‘article’ is always the greatest headache to me because we don’t have this part of speech in our language system (I don’t think Chinese language has it either).

I’ve vaguely learned the rules of articles in English grammar books, but am not really familiar with it.

So when I found the following sentence in the New York Times’ article (December 21), titled, “Looking for a Place to Die,” I was puzzled whether I can say “I have a wife/ She has a husband,” or "I have wife / She has husband."

The patient was a fairly young woman and she’d had cancer for as long as her youngest child had been alive. She had another child, too, a few years older, and a husband whose drawn eyes and tense frame bore the strain of trying to keep it all together. Extended family lived far away and couldn’t be brought closer. The husband and kids lived more than an hour’s drive from the hospital.

When I come across the phrase “She had another child and a husband, I felt like she had one of several husbands she had. Theoretically, you can’t have multiple husbands (or wives) at a time.

When you simply say “I have (she has) husband,” what article should I use, a, the, or non-article?

Follow-up question:

Which is correct, “I have a husband who keeps saying ‘I love you.’ to me," and “I have the husband who keeps saying ‘I love you.’ to me.”?

I’m asking this, because I still remember that I was told at English class of high school more than 60 years ago that the definite article should be used for antecedent (husband in this case) whenever followed by modifier (that) clause.

She has the husband is not correct, as it implies that having a husband is exclusive— that in the current context, only one person can have a husband at the same time, and she is that person. If she has "the" husband, her friend in the same room cannot.

I venture to say this is true whenever "has" meaning "is in possession of" is coupled with the definitely article ("the"); for example, the expression "Smith has the floor" or "Smith has the mic[rophone]" means Smith currently holds the exclusive right to speak at an assembly. Scope and context is important here. If someone asks me why I can't drive somewhere and I explain that "my wife has the car," of course it doesn't mean there is only one car in the world. It means that there is only one car currently at my disposal, and my wife has it.

She has a husband is correct. It is true that one could infer multiple husbands, either in series (i.e. she is divorced or widowed) or in parallel (i.e. she is a polyandrist). In this case, "she had … a husband" but he may not be the same as her current husband. That we do not make such inferences is, I think cultural. English is a Western language, and the tradition in the West is marriage to only one person for life.

"She has husband" is not correct; any singular object of "has" requires an article. The article is omitted for plurals ("she has cars") or conditions or other abstract nouns which lack number ("she has access," "she has courage," "she has pneumonia").

“She has a husband” is correct. I think perhaps your confusion arises from the subtle difference between one and a(n). “She has one husband” is indeed unusual, because it calls attention to the fact that she has precisely one husband, as though she could have more. However, saying “She has a husband” just indicates that, of all the husbands in the world, she happens to be married to one.

In general, the is used to refer to something specific and known, while a(n) typically introduces something indefinite or new, similar to が in Japanese.

She has a new husband. ← Introducing new information (a husband)
The guy is really tall! ← Referring to known information (the guy)

Say you ate an apple.

You cannot say "I ate apple", because its grammatically incorrect. You must say "I ate an apple".

Take these examples too:

• "I have a brain"
• "I have a nose"
• "I have a mouth"

You can't say "I have brain", "I have nose", "I have mouth" even if it is almost certain that you only have ONE brain, ONE nose and ONE mouth.

I think the usage of "a" here is simply for the sake of completing the sentence, so it is grammatically correct.