The English language is full of words that just look alike. There are small differences between them in only one sound, and they usually go together, as a couple, so we call them — minimal pairs.
In English, there are words that differ in a single sound, but this apparently small difference makes a huge one, in the meaning of these words. One of the most popular homophones is definitely “then and than.”
From time to time you might be questioning yourself — did I tell it right; was it grammatically correct; what is the easiest way to improve my grammar and so on. But there is no need to worry about this since there are so many entertaining and easy ways to improve and learn correct grammar.