
"Who" = for people (the one who, who); "that" = for things or animals (that, which).
"Who" always refers to people in relative clauses. Some formal writing styles prefer it for people in all contexts.
The engineer who designed the bridge received a national award for innovation.
She is the kind of person who always finds the positive side of any situation.
Anyone who wishes to participate should sign up before the end of the week.
"That" can refer to both people and things. In everyday speech, "that" for people is perfectly normal, though "who" sounds more formal and precise.
The proposal that was submitted last week has already been approved by the committee.
They adopted the dog that had been living at the shelter for the longest time.
The idea that money cannot buy happiness is more complicated than it first appears.
Common mistake
Trick to remember it
Person = "who"; thing = "that." Test: can you shake hands with it? Yes = "who" ("the engineer who designed it"); no = "that" ("the tool that broke").
Quick rule
Did you know?
The WHO/THAT distinction for people versus things is more fluid than many grammar manuals admit. Corpus linguistics studies show THAT for people appearing in written English since the 14th century, and authors of the caliber of Shakespeare, Chaucer, and the King James Bible used THAT for people regularly. The modern preference for WHO for people was codified mainly by 19th and 20th-century prescriptive grammarians. The most important current style guides (AP, Chicago, APA) prefer WHO for people in formal writing, but none consider THAT a serious error.
Exercise 1 · Pick the right one
I met someone _____ knows you from school. Small world!
Exercise 2 · Pick the right one
The restaurant _____ we visited last week has already closed down.
Exercise 3 · Form the word
'Compose' = the parts make up the whole; 'comprise' = the whole consists of the parts.
"That" introduces essential information; "which" introduces additional, non-essential information (set off by commas).
'A' is used before consonant sounds; 'an' is used before vowel sounds.
'A lot of' works for countable and uncountable; 'many' only for countable; 'much' only for uncountable.
Bryan López
Founder of SpeakUP Academy