diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 06d3a737c5fd36fdd6cc4b0f728014401eeec322..218988e0afc1173f8dba69f4e8f5ba7fdbcaaf31 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -173,7 +173,7 @@ UPDATE branches SET balance = balance + 100.00
    </para>
 
    <para>
-    The details of these commands are unimportant here; the important
+    The details of these commands are not important here; the important
     point is that there are several separate updates involved to accomplish
     this rather simple operation.  Our bank's officers will want to be
     assured that either all these updates happen, or none of them happen.
@@ -428,7 +428,7 @@ SELECT depname, empno, salary, rank() OVER (PARTITION BY depname ORDER BY salary
 
    <para>
     We already saw that <literal>ORDER BY</> can be omitted if the ordering
-    of rows is unimportant.  It is also possible to omit <literal>PARTITION
+    of rows is not important.  It is also possible to omit <literal>PARTITION
     BY</>, in which case there is just one partition containing all the rows.
    </para>
 
diff --git a/doc/src/sgml/ltree.sgml b/doc/src/sgml/ltree.sgml
index 7f127ac49cfd3d036ae7d5f5d89d5ddb25e183fc..06b262bccb82b207772736132a75bdd26f92b2ad 100644
--- a/doc/src/sgml/ltree.sgml
+++ b/doc/src/sgml/ltree.sgml
@@ -160,7 +160,7 @@ Europe &amp; Russia*@ &amp; !Transportation
      This will match paths that contain the label <literal>Europe</literal> and
      any label beginning with <literal>Russia</literal> (case-insensitive),
      but not paths containing the label <literal>Transportation</literal>.
-     The location of these words within the path is unimportant.
+     The location of these words within the path is not important.
      Also, when <literal>%</> is used, the word can be matched to any
      underscore-separated word within a label, regardless of position.
     </para>
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index f496fa880049b7eae30a5f8ef0469c8347c18d0b..a01f9b5fc4eb7e90a5f119b7b4428ba3326101fc 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -2375,7 +2375,7 @@ LANGUAGE SQL IMMUTABLE STRICT;
     <literal>b</literal> inputs will be concatenated, and forced to either
     upper or lower case depending on the <literal>uppercase</literal>
     parameter.  The remaining details of this function
-    definition are unimportant here (see <xref linkend="extend"> for
+    definition are not important here (see <xref linkend="extend"> for
     more information).
    </para>
 
diff --git a/doc/src/sgml/tablefunc.sgml b/doc/src/sgml/tablefunc.sgml
index 520886b811bdad93c8d9579b67851b5e07d8dfcf..cfa20e2a70c9a99e7605a192705550f9a0bdb78a 100644
--- a/doc/src/sgml/tablefunc.sgml
+++ b/doc/src/sgml/tablefunc.sgml
@@ -516,7 +516,7 @@ row_name   extra   cat1   cat2   cat3   cat4
     In practice the <parameter>source_sql</parameter> query should always
     specify <literal>ORDER BY 1</> to ensure that values with the same
     <structfield>row_name</structfield> are brought together.  However,
-    ordering of the categories within a group is unimportant.
+    ordering of the categories within a group is not important.
     Also, it is essential to be sure that the order of the
     <parameter>category_sql</parameter> query's output matches the specified
     output column order.