Than and then are two of the most commonly-confused words in the English language.
These words are nearly identical in spelling and pronunciation. In casual speech, the difference in pronunciation by native English speakers can range from slight to nonexistent. This can, in turn, bleed over into writing, with native speakers using than and then interchangeably. In spite of this tendency, than and then do have distinct roles in the English language. Below is an explanation of when you should use each of these two words.
Than is a conjunction used to help make comparisons. While then has a variety of uses, than can only be used in this one role. Than is also unique in that there are no synonyms for the word. If you can substitute another for word for than in a sentence, then you are using than incorrectly. Here are two examples of than being used in comparisons:
I would rather stand in line all day at the DMV than take my daughter to a boy band concert.
The speaker (presumably a parent) is expressing the idea that he or she would find a boring, tedious activity preferable to having to accompany his or her child to a certain type of musical event.
I like sushi more than my brother does.
Relatively speaking, I enjoy eating sushi to a greater degree, and my brother enjoys eating sushi to a lesser degree.
Then is an adverb. It is commonly used in expressions of time and sequential events but has other uses as well. Below are the various meanings of then in the English language, followed by an example of each.
At that point in time:
I’m sorry I missed your call earlier. I was meeting with a client then.
As the second (or later) step in a sequence of events:
First, I went to work. Then, I had English classes at the English Island in Atlanta. Finally, I went home for a much-needed rest.
As a synonym for “in addition” and related transitions:
We have a lot on our plates at work. There are a dozen new clients that we need to contact, and then there all the existing ones that we must follow up with.
In conditional (“if-then”) sentences:
If Daniel wishes to continue playing soccer, then he needs to improve his grades.
(There is another “if-then” sentence elsewhere in this lesson. See if you can spot it!)