diff --git a/11-if/questions/1-comparison-operators.md b/11-if/questions/1-comparison-operators.md
index cdcaeee..0ce52b9 100644
--- a/11-if/questions/1-comparison-operators.md
+++ b/11-if/questions/1-comparison-operators.md
@@ -3,10 +3,10 @@
 2. `!=`
 3. `>` *CORRECT*
 
-> **3:** That's the greater operator. It checks whether a ordered value is greater than the other or not.
+> **3:** That's the greater operator. It checks whether an ordered value is greater than the other or not.
 
 
-## Which one below is not one of the comparison operators of Go?
+## Which one below is not one of the ordering operators of Go?
 1. `>`
 2. `<=`
 3. `==` *CORRECT*
@@ -24,7 +24,7 @@
 > **3:** That's right. All the comparison operators return an untyped bool value (true or false).
 
 
-## Which one of these cannot be used as an operand to ordering operators (`>`, `<`, `>=`, `<=`)?
+## Which one of these below cannot be used as an operand to ordering operators (`>`, `<`, `>=`, `<=`)?
 1. int value
 2. byte value
 3. string value
diff --git a/11-if/questions/2-logical-operators.md b/11-if/questions/2-logical-operators.md
index e674f3c..2230cdb 100644
--- a/11-if/questions/2-logical-operators.md
+++ b/11-if/questions/2-logical-operators.md
@@ -117,7 +117,7 @@ func main() {
 
 // Don't mind about these functions.
 // Just focus on the problem.
-// These are here just for you to understand it better.
+// They are here just for you to understand what's going on better.
 func super() bool {
     fmt.Print("super ")
     return true
diff --git a/11-if/questions/3-if.md b/11-if/questions/3-if.md
index 2e8739c..5938054 100644
--- a/11-if/questions/3-if.md
+++ b/11-if/questions/3-if.md
@@ -79,7 +79,7 @@ func main() {
 >
 > **3:** Perfect! You don't need to compare the value to `true`. `happy` is already true, so it'll print "cool!".
 >
-> **4:** That won't print anything. `happy` will be true.
+> **4:** That won't print anything. `!happy` yields false.
 
 
 ## How can you simplify the following code? You only need to change the condition expression, but how?
@@ -108,7 +108,7 @@ func main() {
 > **4:** That won't print anything. `happy` will be true.
 
 
-## Is this code going to work? Why?
+## This code contains an error. How to fix it?
 ```go
 package main
 
diff --git a/11-if/questions/4-error-handling.md b/11-if/questions/4-error-handling.md
index faabeb9..d27e8b8 100644
--- a/11-if/questions/4-error-handling.md
+++ b/11-if/questions/4-error-handling.md
@@ -1,3 +1,16 @@
+## Why error handling is needed?
+1. I don't know.
+2. To control the execution flow.
+3. To make a program malware safe.
+4. Because, things can go wrong. *CORRECT*
+
+> **1:** Then, please watch the lecture again! :)
+>
+> **2:** Actually yes, but that's not the main reason. 
+> 
+> **3:** Come on!
+
+
 ## What's a nil value?
 1. The dark matter that rules the universe.
 2. It's a zero value for pointers or pointer-based types. It means the value is uninitialized. *CORRECT*
@@ -13,25 +26,12 @@
 > 
 
 
-## Why error handling is needed?
-1. I don't know.
-2. To control the execution flow.
-3. To make a program malware safe.
-4. Because, things can go wrong. *CORRECT*
-
-> **1:** Then, please rewatch the lecture! :)
->
-> **2:** Actually yes, but that's not the main reason. 
-> 
-> **3:** Come on!
-
-
 ## How Go handles error handling?
-1. Using a throw/catch block
+1. Using a throw/catch statement
 2. Using a simple if statement with nil comparison *CORRECT*
 3. Using a mechanism called tagging
 
-> **1:** There isn't a throw/catch block in Go; unlike Java, C#, and so on... Go is explicit.
+> **1:** There isn't a throw/catch statement in Go; unlike Java, C#, and so on... Go is explicit.
 
 
 ## When you should handle the errors?
diff --git a/11-if/questions/5-short-if.md b/11-if/questions/5-short-if.md
index 4463951..1aa4406 100644
--- a/11-if/questions/5-short-if.md
+++ b/11-if/questions/5-short-if.md
@@ -62,7 +62,7 @@ func main() {
 3. Change the done declaration of the main() to an assignment
 4. Change the done declaration of the short-if to an assignment. And, after the if statement, assign false back to the done variable. *CORRECT*
 
-> **1:** That will break the program. The last line tries to print it.
+> **1:** That will break the program. Because, the last line prints it.
 > 
 > **2:** The program wants to use it to print true.
 > 
diff --git a/12-switch/exercises/00/main.go b/12-switch/exercises/00/main.go
deleted file mode 100644
index 1bace58..0000000
--- a/12-switch/exercises/00/main.go
+++ /dev/null
@@ -1,22 +0,0 @@
-// For more tutorials: https://blog.learngoprogramming.com
-//
-// Copyright © 2018 Inanc Gumus
-// Learn Go Programming Course
-// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
-//
-
-package main
-
-// ---------------------------------------------------------
-// EXERCISE
-//  ?
-//
-// NOTE
-//  ?
-//
-// EXPECTED OUTPUT
-//  ?
-// ---------------------------------------------------------
-
-func main() {
-}
diff --git a/12-switch/exercises/00/solution/main.go b/12-switch/exercises/00/solution/main.go
deleted file mode 100644
index b5e729e..0000000
--- a/12-switch/exercises/00/solution/main.go
+++ /dev/null
@@ -1,11 +0,0 @@
-// For more tutorials: https://blog.learngoprogramming.com
-//
-// Copyright © 2018 Inanc Gumus
-// Learn Go Programming Course
-// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
-//
-
-package main
-
-func main() {
-}