diff --git a/Advanced/Mock a Mockingbird/parts/02 kestrel.tex b/Advanced/Mock a Mockingbird/parts/02 kestrel.tex
index 0e4f900..293b508 100644
--- a/Advanced/Mock a Mockingbird/parts/02 kestrel.tex	
+++ b/Advanced/Mock a Mockingbird/parts/02 kestrel.tex	
@@ -1,7 +1,7 @@
 \section{The Curious Kestrel}
 
 \definition{}
-Recall that a bird is \textit{egocenteric} if it is fond of itself. \\
+Recall that a bird is \textit{egocentric} if it is fond of itself. \\
 A bird is \textit{hopelessly egocentric} if $Bx = B$ for all birds $x$.
 
 \definition{}
@@ -33,7 +33,7 @@ $$
 In other words, this means that for every bird $x$, the bird $Kx$ is fixated on $x$.
 
 \problem{}
-Show that an egocenteric Kestrel is hopelessly egocentric.
+Show that an egocentric Kestrel is hopelessly egocentric.
 
 \begin{solution}
 	\begin{alltt}
@@ -58,7 +58,7 @@ Given the Law of Composition and the Law of the Mockingbird, show that at least
 \end{helpbox}
 
 \begin{solution}
-	The final piece is a lemma we proved earler: \\
+	The final piece is a lemma we proved earlier: \\
 	Any bird is fond of at least one bird
 
 	\begin{alltt}
@@ -115,7 +115,7 @@ Show that if $K$ is fond of $Kx$, $K$ is fond of $x$.
 An egocentric Kestrel must be extremely lonely. Why is this?
 
 \begin{solution}
-	If a Kestrel is egocenteric, it must be the only bird in the forest!
+	If a Kestrel is egocentric, it must be the only bird in the forest!
 
 	\begin{alltt}
 		\lineno{} \cmnt{Given}