That vs. Which vs. Who

The problem arises when combining clauses.

Grammar used to teach “that” as indicating the following clause to be defining and “which” to be explanatory. Careful use of commas for explanatory clauses would eliminate confusion when using “that” or “which” interchangeably.

When the clause refers to people, “who” should be used.

Current writing tends to leave “that” out before the second clause.

Examples:

• Chicken Little thought (that) the sky was about to fall.
• He ran around telling everyone (that) they should take cover.
• Nobody believed (that) he knew what he was saying.

“That” or “which” identifying a noun

Traditionally, “that” was used for identifying a specific one, and “which” added descriptive information which did not specifically identify. That distinction is fading. To complicate matters, “that” or “which” is often omitted.

Traditional examples:

• The bone (that) the dog buried came from the boy’s supper.
  • Identifies which bone the dog buried
• The bone (which) the dog buried came from the boys supper.
  • Explains what the dog did with the bone

Punctuation can solve the problem. Commas surround non-essential information.

• The bone that the dog buried came from the boy’s supper.
  • Identifies which bone the dog buried
• The bone, (that/which) the dog buried, came from the boy’s supper.
  • Explains what the dog did with the bone
  • The main sentence tells us the important information, the source of the bone.

• The old grammar book, (that/which) I found in the attic, explained the puzzle to me.
  • (“The old grammar book explained the puzzle to me” is a complete sentence with full meaning. This makes sense with or without knowing that it was found in the attic.)

“Which” as a choice

“Which” can be the question or the answer, used as either a pronoun or an adjective.

Examples as pronoun:

• (presenting two bowls of ice cream) “Which do you want?”
• (asked about two teams) “I don’t know which won, but they did not both lose.”

Examples as adjective:

• Which book did you read last night?
• I didn’t know which author I would prefer, so I didn’t read either.
• Which writer makes the most money?
• If I knew which house he lived in, I might take a guess.
• You can check the internet to find out which book sold the most copies.

“Who” refers to people

In general, “who” should be used when identifying or explaining about people. “That” or “which” refers to things. Which you use for animals probably depends upon your relationship to the specific animal.

• The boy who gave the dog the bone did not finish his supper.
  • Identifies which boy gave the dog the bone
• The boy, who gave the dog the bone, did not finish his supper.
  • Adds information about the boy, information not necessary for the sentence, although it may be helpful for the reader
  • The sentence tells us that the boy did not finish his supper. The added (non-essential) information is that he gave his bone to the dog.

• The only grammarian who will notice this is one who has taught for 40 years.
  • (A grammarian is a person, so “who” is preferred.)
  • (“Who will notice this” is needed in the sentence, so no comma.)
• Cyrus, who is a grammarian, taught for 40 years.
  • (Cyrus is a person, so “who” is preferred.)
  • (“Who is a grammarian” is not necessary in the sentence, so it should be surrounded by commas.)

That (as in “this, that, these, those”)

“That,” as a demonstrative pronoun (“this,” “that,” “these,” “those”) can be a subject.

Examples:

• That’ll be the day when you make me cry. (Buddy Holly or Linda Ronstadt)
• That is my book, not yours.
• This is hard, making up sentences.
• These sometimes relate to each other, but sometimes they don’t.

These same four words may serve as demonstrative adjectives, referring to nouns.

• That day made me very sad.
• That book was written by my great grandfather about the Civil War.
• This sentence will be the next-to-the-last sentence on this page.
• Repeating this word (“sentence”) in the same sentence is bad writing.

Credit: Photo by Annie Spratt, Photo by Bruno Wolff, Photo by Caleb Woods on Unsplash