diff --git a/s48/concurrency/README b/s48/concurrency/README
index 12dd129..033c42b 100644
--- a/s48/concurrency/README
+++ b/s48/concurrency/README
@@ -6,7 +6,7 @@ by using a counter for the free slots of the resource.
 
 (make-semaphore init) -> semaphore
 
-Constuctor for semaphores. INIT specifies the initial value of the
+Constructor for semaphores. INIT specifies the initial value of the
 semaphore's counter.
 
 
@@ -27,7 +27,7 @@ Increments the counter of the semaphore SEM.
 Calls SEMAPHORE-WAIT on SEM before calling THUNK. When THUNK returns,
 calls SEMAPHORE-POST on SEM and returns the return value of THUNK. If
 the evaluation of THUNK causes a non-local exit, SEMAPHORE-POST is
-also applied to SEM, likwise, if the control reenters the dynamic
+also applied to SEM, likewise, if the control reenters the dynamic
 extend of the evaluation of THUNK, SEMAPHORE-WAIT is called on SEM.
 
 
diff --git a/s48/module-system/README b/s48/module-system/README
index 4d8c24b..879b420 100644
--- a/s48/module-system/README
+++ b/s48/module-system/README
@@ -39,16 +39,16 @@ Loads config file containing structure definition. This is the same as
 in the REPL.
 
 
-(reify-structure structure-name) --> #{Rt-stucture surflet} 
+(reify-structure structure-name) --> rt-structure
 
 Creates a rt-structure object representing the structure which name
-STRUCUTURE-NAME (a symbol).
+STRUCTURE-NAME (a symbol).
 
 
 
 (load-structure rt-structure) --> unspecific
 
-Ensures that the definition of the unterlying structure has been
+Ensures that the definition of the underlying structure has been
 loaded. This is the same as
 
 ,load-package structure
diff --git a/scsh/pps/README b/scsh/pps/README
index 9b30330..930be68 100644
--- a/scsh/pps/README
+++ b/scsh/pps/README
@@ -1,4 +1,4 @@
-The stucture pps implements a portable version of the ps command. It
+The structure pps implements a portable version of the ps command. It
 currently supports FreeBSD (4.6), Mac OS X/Darwin (10.2/6.3), Linux
 (2.4.19), AIX (4.3.2), Solaris (SunOS 5.8) (tested version). As the ps
 command is not part of any standard this package is likely to fail if