Fix typo "assemble then" -> "assemble them"
@@ -158,7 +158,7 @@ software like [lex](https://en.wikipedia.org/wiki/Lex_(software)) and
[yacc](https://en.wikipedia.org/wiki/Yacc). Instead of writing the grammar
in a separate file and generating the corresponding code, you use very
small functions with very specific purpose, like "take 5 bytes", or
-"recognize the word 'HTTP'", and assemble then in meaningful patterns
+"recognize the word 'HTTP'", and assemble them in meaningful patterns
like "recognize 'HTTP', then a space, then a version".
The resulting code is small, and looks like the grammar you would have
written with other parser approaches.
