Msc spelling and grammar fixes for concepts and concept exercises.

concepts/basics/introduction.md

@@ -89,7 +89,7 @@ def add_two_numbers(number_one, number_two):
 # the variable will also return the value.
 >>> sum_with_return = add_two_numbers(5, 6)
 >>> print(sum_with_return)
-7
+11
 ```
 
 Functions that do not have an _explicit_ `return` expression will _implicitly_ return the [`None`][none] object.

concepts/classes/about.md

@@ -314,12 +314,12 @@ class MyClass:
 
     # This will compile and run without error, but has no current functionality.
     def pending_functionality(self):
-       # Stubbing or placholding the body of this method.
+       # Stubbing or place-holding the body of this method.
        pass
 ```
 
 [class method]: https://stackoverflow.com/questions/17134653/difference-between-class-and-instance-methods
-[dunder]: https://www.dataindependent.com/python/python-glossary/python-dunder/
+[dunder]: https://mathspp.com/blog/pydonts/dunder-methods
 [oop]: https://www.educative.io/blog/object-oriented-programming
 [dot notation]: https://stackoverflow.com/questions/45179186/understanding-the-dot-notation-in-python
 [shadowing]: https://oznetnerd.com/2017/07/17/python-shadowing/

concepts/conditionals/about.md

@@ -92,13 +92,13 @@ Conditionals can also be nested.
 
 
 >>> driving_status(63, 78)
-'Unlicsensed!'
+'Unlicensed!'
 
 >>> driving_status(16, 81)
 'Student driver, needs supervision.'
 
 >>> driving_status(23, 80)
-'Fully licsensed driver.'
+'Fully licensed driver.'
 ```
 
 ## Conditional expressions or "ternary operators"

exercises/concept/black-jack/.docs/instructions.md

@@ -79,15 +79,15 @@ Remember: the value of the hand with the ace needs to be as high as possible _wi
 
 ## 4. Determine a "Natural" or "Blackjack" Hand
 
-If the first two cards a player is dealt are an ace (A) and a ten-card (_10, K , Q or J_), then the player has a score of 21. 
-This is known as a blackjack hand. 
+If a player is dealt an ace (`A`) and a ten-card (10, `K`, `Q`, or `J`) as their first two cards, then the player has a score of 21.
+This is known as a **blackjack** hand.
 
 
 Define the `is_blackjack(<card_one>, <card_two>)` function with parameters `card_one` and `card_two`, which are a pair of cards.
-Determine if the two-card hand is a `blackjack`, and return the boolean `True` if it is, `False` otherwise.
+Determine if the two-card hand is a **blackjack**, and return the boolean `True` if it is, `False` otherwise.
 
 **Note** : The score _calculation_ can be done in many ways.
-But if possible, we'd like you to check if there is an ace and a ten-card **_in_** the hand (or at a certain position), as opposed to _summing_ the hand values.
+But if possible, we'd like you to check if there is an ace and a ten-card **_in_** the hand (_or at a certain position_), as opposed to _summing_ the hand values.
 
 ```python
 >>> is_blackjack('A', 'K')

exercises/concept/ellens-alien-game/.docs/introduction.md

@@ -261,7 +261,7 @@ class MyClass:
 
 [calling]: https://www.pythonmorsels.com/topics/calling-a-function
 [class method]: https://stackoverflow.com/questions/17134653/difference-between-class-and-instance-methods
-[dunder]: https://www.dataindependent.com/python/python-glossary/python-dunder/
+[dunder]: https://mathspp.com/blog/pydonts/dunder-methods
 [imperative]: https://en.wikipedia.org/wiki/Imperative_programming
 [declarative]: https://en.wikipedia.org/wiki/Declarative_programming
 [oop]: https://www.digitalocean.com/community/tutorials/how-to-construct-classes-and-define-objects-in-python-3

exercises/concept/guidos-gorgeous-lasagna/.docs/introduction.md

@@ -100,8 +100,8 @@ def add_two_numbers(number_one, number_two):
 >>> add_two_numbers(3, 4)
 7
 
-# Assigning the function call to a variable and printing 
-# the variable will also return the value.
+# Assigning the function call to a variable and printing it 
+# will also return the value.
 >>> sum_with_return = add_two_numbers(5, 6)
 >>> print(sum_with_return)
 11
@@ -153,7 +153,7 @@ Dot (`.`) notation is used for calling functions defined inside a class or modul
 27
 
 
-# A mis-match between the number of parameters and the number of arguments will raise an error.
+# A mismatch between the number of parameters and the number of arguments will raise an error.
 >>> number_to_the_power_of(4,)
 ...
 Traceback (most recent call last):