“Then” and “than” look and sound similar but they mean very different things.

THEN is an adverb, referring to a certain time, or “when” something happened or will happen. For example:

  • “Let’s meet at 3 pm.” 
  • “Sounds good! I’ll see you then.” (“then” = 3 pm)
  • “I had dinner and then went to bed.” (“then” = after dinner)
  • “The clouds were pretty and white, but then they turned gray and dark.” (“then” = later)
  • “What happened then?” (“then” = after turning gray and dark)
  • “It began to rain.”

THAN, a conjunction, connects other words or phrases that are often comparisons: “bigger than,” “earlier than,” “less common than,” etc.  

English learners often confuse “than” and “as”.  

Here is the difference:

THAN is used to compare things that are different in size, weight, importance: “better than,” “more difficult than,” etc.

  • New York is bigger than Boston. 
  • Your coffee tastes better than mine.

AS … AS is used to compare things of equal size, weight, importance: “as small as,” “as good as,” etc.  For example:

  • I like the beach as much as the mountains.
  • John’s apartment is not as small as Andy’s.

Grammar Notes 

  1. Different than vs different from – both forms are standard and acceptable
  • Bill’s shirt is different from mine.
  • Bill’s shirt is different than mine.”
  1. Taller than me vs Taller than I
  • Sarah is taller than I.  (This is wrong. It sounds old-fashioned and is rarely used.)
  • (standard) Sarah is taller than I am. 
  • (new standard) Sarah is taller than me.

THAN is also used with “rather” to state a preference: 

I would rather travel by train than by plane. 

“Rather than” is used by native speakers more often than “prefer,” which has a more formal sound. The American musician Paul Simon uses “rather than” several times in this song (with lyrics), which begins, “I’d rather be a sparrow than a snail.”