diff --git a/doc/source/manual/background.rst b/doc/source/manual/background.rst
index d43c80a5..38bfc0e5 100644
--- a/doc/source/manual/background.rst
+++ b/doc/source/manual/background.rst
@@ -13,7 +13,7 @@ Prerequisites
 =============
 
 You need a basic understanding of Python to use MyHDL. If you don't know Python,
-don't worry: it it is one of the easiest programming languages to learn  [#]_.
+don't worry: it is is one of the easiest programming languages to learn  [#]_.
 Learning Python is one of the best time investments that engineering
 professionals can make  [#]_.
 
@@ -119,9 +119,9 @@ About decorators
 
 .. index:: single: decorators; about
 
-Python 2.4 introduced a new feature called decorators. MyHDL takes advantage
-of this new feature by defining a number of decorators that facilitate hardware
-descriptions. However, many users may not yet be familiar with decorators.
+Python 2.4 introduced a feature called decorators. MyHDL takes advantage
+of this feature by defining a number of decorators that facilitate hardware
+descriptions. However, some users may not yet be familiar with decorators.
 Therefore, an introduction is included here.
 
 A decorator consists of special syntax in front of a function declaration. It
diff --git a/doc/source/manual/preface.rst b/doc/source/manual/preface.rst
index bccf31bb..42be5285 100644
--- a/doc/source/manual/preface.rst
+++ b/doc/source/manual/preface.rst
@@ -48,9 +48,9 @@ designs, by co-simulation with traditional HDL simulators.
 
 Subject to some limitations, MyHDL designs can be converted to Verilog
 or VHDL.  This provides a path into a traditional design flow,
-including synthesis and implementation.  However, the convertible
-subset is much wider than the standard synthesis subset, and includes
-features that can be used for high level modeling and test benches.
+including synthesis and implementation.  The convertible
+subset is restricted, but much wider than the standard synthesis subset.
+It includes features that can be used for high level modeling and test benches.
 
 The converter works on an instantiated design that has been
 fully elaborated. Consequently, the original design structure can be