Improve doc strings

Co-authored-by: Sadie L. Bartholomew <sadie.bartholomew@ncas.ac.uk>

Author: davidhassell

cf/data/data.py

@@ -7384,7 +7384,7 @@ def to_memory(self):
     def to_units(self, units, inplace=False):
         """Change the data array units.
 
-        Changing the units will causes the data values to be changed
+        Changing the units causes the data values to be changed
         to match the new units, therefore the new units must be
         equivalent to the existing ones.
 

cf/mixin/propertiesdata.py

@@ -4435,7 +4435,7 @@ def to_dask_array(self):
     def to_units(self, units, inplace=False):
         """Change the data array units.
 
-        Changing the units will causes the data values to be changed
+        Changing the units causes the data values to be changed
         to match the new units, therefore the new units must be
         equivalent to the existing ones.
 

cf/mixin/propertiesdatabounds.py

@@ -2246,8 +2246,8 @@ def override_units(self, units, inplace=False, i=False):
 
         Not to be confused with changing to equivalent units with the
         `to_units` method or the `Units`, `units`, or `calendar`
-        attributes. These approaches also convert the data to have the
-        new units.
+        attributes. These approaches also convert the data values to conform
+        with the new units.
 
         .. seealso:: `override_calendar`, `to_units`, `Units`,
                      `units`, `calendar`
@@ -3324,7 +3324,7 @@ def log(self, base=None, bounds=True, inplace=False, i=False):
     def to_units(self, units, inplace=False):
         """Change the data array units.
 
-        Changing the units will causes the data values to be changed
+        Changing the units causes the data values to be changed
         to match the new units, therefore the new units must be
         equivalent to the existing ones.