diff --git a/Tools/cases_generator/interpreter_definition.md b/Tools/cases_generator/interpreter_definition.md
index d50c420307852f..7901f3d92e00bb 100644
--- a/Tools/cases_generator/interpreter_definition.md
+++ b/Tools/cases_generator/interpreter_definition.md
@@ -174,7 +174,7 @@ list of annotations and their meanings are as follows:
 * `override`. For external use by other interpreter definitions to override the current
    instruction definition.
 * `pure`. This instruction has no side effects.
-* 'tierN'. This instruction only used by tier N interpreter.
+* 'tierN'. This instruction is only used by the tier N interpreter.
 
 ### Special functions/macros
 
@@ -393,7 +393,7 @@ which can be easily inserted. What is more complex is ensuring the correct stack
 and not generating excess pops and pushes.
 
 For example, in `CHECK_HAS_INSTANCE_VALUES`, `owner` occurs in the input, so it cannot be
-redefined. Thus it doesn't need to be written and can be read without adjusting the stack pointer.
+redefined. Thus, it doesn't need to be written and can be read without adjusting the stack pointer.
 The C code generated for `CHECK_HAS_INSTANCE_VALUES` would look something like:
 
 ```C
@@ -404,7 +404,7 @@ The C code generated for `CHECK_HAS_INSTANCE_VALUES` would look something like:
     }
 ```
 
-When combining ops together to form instructions, temporary values should be used,
+When combining ops to form instructions, temporary values should be used,
 rather than popping and pushing, such that `LOAD_ATTR_SLOT` would look something like:
 
 ```C