Typo fix
diff --git a/docs/primitives/symmetric-encryption.rst b/docs/primitives/symmetric-encryption.rst
index 779f087..fe074f3 100644
--- a/docs/primitives/symmetric-encryption.rst
+++ b/docs/primitives/symmetric-encryption.rst
@@ -7,8 +7,8 @@
.. class:: cryptography.primitives.block.BlockCipher(cipher, mode)
Block ciphers work by encrypting content in chunks, often 64- or 128-bits.
- Theycombine an underlying algorithm (such as AES), with a mode (such as CBC,
- CTR, or GCM). A simple example of encrypting content with AES is:
+ They combine an underlying algorithm (such as AES), with a mode (such as
+ CBC, CTR, or GCM). A simple example of encrypting content with AES is:
.. code-block:: pycon