diff --git a/include/ChangeLog b/include/ChangeLog
index 207bfa81915dbda6fa0f738d62ef3ab1737616d7..8be8343a78e71d8ee7f6fc874e6debe6f592380c 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,10 @@
+2019-01-09  Sandra Loosemore  <sandra@codesourcery.com>
+
+	PR other/16615
+
+	* libiberty.h: Mechanically replace "can not" with "cannot".
+	* plugin-api.h: Likewise.
+
 2019-01-01  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.
diff --git a/include/libiberty.h b/include/libiberty.h
index d9c0b259cb4b148d215cd37a87c5527a50f8a66d..574761350267b1eaa281343a11fe5dd5c737f9e5 100644
--- a/include/libiberty.h
+++ b/include/libiberty.h
@@ -558,7 +558,7 @@ extern FILE *pex_input_file (struct pex_obj *obj, int flags,
 extern FILE *pex_input_pipe (struct pex_obj *obj, int binary);
 
 /* Read the standard output of the last program to be executed.
-   pex_run can not be called after this.  BINARY should be non-zero if
+   pex_run cannot be called after this.  BINARY should be non-zero if
    the file should be opened in binary mode; this is ignored on Unix.
    Returns NULL on error.  Don't call fclose on the returned FILE; it
    will be closed by pex_free.  */
@@ -566,7 +566,7 @@ extern FILE *pex_input_pipe (struct pex_obj *obj, int binary);
 extern FILE *pex_read_output (struct pex_obj *, int binary);
 
 /* Read the standard error of the last program to be executed.
-   pex_run can not be called after this.  BINARY should be non-zero if
+   pex_run cannot be called after this.  BINARY should be non-zero if
    the file should be opened in binary mode; this is ignored on Unix.
    Returns NULL on error.  Don't call fclose on the returned FILE; it
    will be closed by pex_free.  */
diff --git a/include/plugin-api.h b/include/plugin-api.h
index 174f01cbab0ca8a7b06ea5bc4ed9b7076176b23a..2076bdaae655e23c581bc170fe10630240fab476 100644
--- a/include/plugin-api.h
+++ b/include/plugin-api.h
@@ -34,7 +34,7 @@
 #include <sys/types.h>
 #if !defined(HAVE_STDINT_H) && !defined(HAVE_INTTYPES_H) && \
     !defined(UINT64_MAX) && !defined(uint64_t)
-#error can not find uint64_t type
+#error cannot find uint64_t type
 #endif
 
 #ifdef __cplusplus
diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 436fb96255ce5b895ad86dd8d077e7b3a869f7cd..2206b91d3baec07767a433c908981248e779235b 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,11 @@
+2019-01-09  Sandra Loosemore  <sandra@codesourcery.com>
+
+	PR other/16615
+
+	* cp-demangle.c: Mechanically replace "can not" with "cannot".
+	* floatformat.c: Likewise.
+	* strerror.c: Likewise.
+
 2019-01-01  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.
diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index 4624cd5fb2f93d3e5339e6d78a34cd23f88f605d..ddcd3be6b8f524c91a12f131d657e68cf0886100 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -6201,13 +6201,13 @@ cplus_demangle_init_info (const char *mangled, int options, size_t len,
 
   di->n = mangled;
 
-  /* We can not need more components than twice the number of chars in
+  /* We cannot need more components than twice the number of chars in
      the mangled string.  Most components correspond directly to
      chars, but the ARGLIST types are exceptions.  */
   di->num_comps = 2 * len;
   di->next_comp = 0;
 
-  /* Similarly, we can not need more substitutions than there are
+  /* Similarly, we cannot need more substitutions than there are
      chars in the mangled string.  */
   di->num_subs = len;
   di->next_sub = 0;
diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c
index 2c6c6abe77fb233ee6cbf8715b0450e99d2327a9..8632253b4c14f4341384c814db8dc48d9de0f683 100644
--- a/libiberty/floatformat.c
+++ b/libiberty/floatformat.c
@@ -489,7 +489,7 @@ floatformat_to_double (const struct floatformat *fmt,
       int nan = mant_bits_set (fmt, ufrom);
 
       /* On certain systems (such as GNU/Linux), the use of the
-	 INFINITY macro below may generate a warning that can not be
+	 INFINITY macro below may generate a warning that cannot be
 	 silenced due to a bug in GCC (PR preprocessor/11931).  The
 	 preprocessor fails to recognise the __extension__ keyword in
 	 conjunction with the GNU/C99 extension for hexadecimal
diff --git a/libiberty/strerror.c b/libiberty/strerror.c
index a8a0bd1f7e2c99f19b0f5d7560734331efe792e1..cc7692c1d6951ce7008b59d7f93766777d256547 100644
--- a/libiberty/strerror.c
+++ b/libiberty/strerror.c
@@ -299,7 +299,7 @@ static const struct error_info error_table[] =
   ENTRY(EREMCHG, "EREMCHG", "Remote address changed"),
 #endif
 #if defined (ELIBACC)
-  ENTRY(ELIBACC, "ELIBACC", "Can not access a needed shared library"),
+  ENTRY(ELIBACC, "ELIBACC", "Cannot access a needed shared library"),
 #endif
 #if defined (ELIBBAD)
   ENTRY(ELIBBAD, "ELIBBAD", "Accessing a corrupted shared library"),