Doc: fix typos, patch written by Stefan Behnel

Doc/c-api/memory.rst

@@ -363,7 +363,7 @@ Customize Memory Allocators
       This function now also works on Python compiled in release mode.
       On error, the debug hooks now use :mod:`tracemalloc` to get the traceback
       where a memory block was allocated. The debug hooks now also check
-      if the GIL is hold when functions of :c:data:`PYMEM_DOMAIN_OBJ` and
+      if the GIL is held when functions of :c:data:`PYMEM_DOMAIN_OBJ` and
       :c:data:`PYMEM_DOMAIN_MEM` domains are called.
 
 

Doc/using/cmdline.rst

@@ -639,11 +639,11 @@ conflict.
 
    * ``debug``: install debug hooks on top of the default memory allocator
    * ``malloc_debug``: same as ``malloc`` but also install debug hooks
-   * ``pymalloc_debug``: same as ``pyalloc`` but also install debug hooks
+   * ``pymalloc_debug``: same as ``pymalloc`` but also install debug hooks
 
-   When is compiled in release mode, the default is ``pymalloc``. When Python
-   is compiled in debug mode, the default is ``pymalloc_debug``: debug hooks
-   are installed.
+   When Python is compiled in release mode, the default is ``pymalloc``. When
+   compiled in debug mode, the default is ``pymalloc_debug`` and the debug hooks
+   are used automatically.
 
    If Python is configured without ``pymalloc`` support, ``pymalloc`` and
    ``pymalloc_debug`` are not available, the default is ``malloc`` in release

Doc/whatsnew/3.6.rst

@@ -121,7 +121,7 @@ compiled in release mode using ``PYTHONMALLOC=debug``. Effects of debug hooks:
   functions of :c:data:`PYMEM_DOMAIN_OBJ` (ex: :c:func:`PyObject_Malloc`) and
   :c:data:`PYMEM_DOMAIN_MEM` (ex: :c:func:`PyMem_Malloc`) domains are called.
 
-Checking if the GIL is hold is also a new feature of Python 3.6.
+Checking if the GIL is held is also a new feature of Python 3.6.
 
 See the :c:func:`PyMem_SetupDebugHooks` function for debug hooks on Python
 memory allocators.