diff --git a/quick2wire/parts/mcp23x17.py b/quick2wire/parts/mcp23x17.py
index dc8bd66..bce4f53 100644
--- a/quick2wire/parts/mcp23x17.py
+++ b/quick2wire/parts/mcp23x17.py
@@ -15,7 +15,7 @@
 In = "in"
 Out = "out"
 
-# Bits within the IOCON regiseter
+# Bits within the IOCON register
 IOCON_INTPOL=1
 IOCON_ODR=2
 IOCON_MIRROR=6
diff --git a/quick2wire/selector.py b/quick2wire/selector.py
index 01479b0..c66453e 100644
--- a/quick2wire/selector.py
+++ b/quick2wire/selector.py
@@ -58,7 +58,7 @@ def add(self, source, eventmask=INPUT|ERROR, trigger=None, identifier=None):
                                         the source
                       OUTPUT         -- output can be written to the source
                       ERROR          -- an error has occurred on the source
-                      HANGUP         -- a remote hangup has occured on the 
+                      HANGUP         -- a remote hangup has occurred on the 
                                         source
                       PRIORITY_INPUT -- urgent out-of-band data is waiting 
                                         to be read from the source
@@ -130,7 +130,7 @@ def has_error(self):
     
     @property
     def has_hangup(self):
-        """Returns whether a remote hangup has occured on the ready event source."""
+        """Returns whether a remote hangup has occurred on the ready event source."""
         return bool(self.events & HANGUP)
     
     @property
diff --git a/quick2wire/spi_ctypes.py b/quick2wire/spi_ctypes.py
index 5c10df3..8181341 100644
--- a/quick2wire/spi_ctypes.py
+++ b/quick2wire/spi_ctypes.py
@@ -46,7 +46,7 @@
 # are in a different address space (and may be of different sizes in some
 # cases, such as 32-bit i386 userspace over a 64-bit x86_64 kernel).
 # Zero-initialize the structure, including currently unused fields, to
-# accomodate potential future updates.
+# accommodate potential future updates.
 #
 # SPI_IOC_MESSAGE gives userspace the equivalent of kernel spi_sync().
 # Pass it an array of related transfers, they'll execute together.