diff --git a/02_read/main b/02_read/main
new file mode 100755
index 0000000..8c75e43
Binary files /dev/null and b/02_read/main differ
diff --git a/15_enums/function_types.v b/15_enums/function_types.v
new file mode 100644
index 0000000..239770b
--- /dev/null
+++ b/15_enums/function_types.v
@@ -0,0 +1,38 @@
+
+
+type Filter = fn (string) string
+
+
+fn filter(s string, f Filter) string{
+	return f(s)
+}
+
+fn uppercase(s string) string{
+	return s.to_upper()
+}
+
+
+type String = string
+
+
+fn (s String) my_upper() string{
+	return s.to_upper()
+}
+
+fn main(){
+
+	res := filter('Teste', fn (s string) string {
+		return s
+	})
+
+	println(res)
+
+	println(uppercase('teste'))
+
+	mut str := String('oi')
+	println(str)
+	println(str.my_upper())
+
+	my_filter := Filter(uppercase)
+	println(my_filter)
+}
\ No newline at end of file
diff --git a/15_enums/main.v b/15_enums/main.v
index 1724b1f..c25b226 100644
--- a/15_enums/main.v
+++ b/15_enums/main.v
@@ -1,36 +1,72 @@
-enum Color as u8{
+enum Color as u8 {
 	@none
 	red
 	green
 	blue
 }
 
-pub fn main(){
 
+enum Grocery{
+	apple
+	orange = 5
+	pear
+}
+
+
+enum Cycle{
+	one 
+	two
+	three
+}
+
+
+fn (c Cycle) next() Cycle{
+
+	match c {
+		.one {
+			return .two
+		}
+
+		.two {
+			return .three
+		}
+
+		.three {
+			return .one
+		}
+	}
+}
+
+
+fn main(){
 	mut color := Color.red
+
 	color = .green
-
-	mut color1 := Color.@none
-
 	println(color)
 
 	match color {
-		.red {
-			println('the color was red')
-		}
-
-		.green {
-			println('the color was green')
-		}
-
-		.blue {
-			println('the color was blue')
-		}
-
-		else {
-			println('color was not indentified')
-		}
+		.red { println('The color was red') }
+		.green { println('The color was green')}
+		.blue { println('The color was blue ')}
+		else { println('The value is none')}
 	}
 
-	println(color1)
-}
+	color = Color.@none
+	println(color)
+
+
+	g1 := int(Grocery.apple)
+	g2 := int(Grocery.orange)
+	g3 := int(Grocery.pear)
+
+	println('Grocery ids ${g1}, ${g2}, ${g3}')
+
+
+	mut c := Cycle.one
+
+	for _ in 0..10 {
+		println(c)
+		c = c.next()
+	}
+
+}
\ No newline at end of file
diff --git a/15_enums/type.v b/15_enums/type.v
new file mode 100644
index 0000000..605500e
--- /dev/null
+++ b/15_enums/type.v
@@ -0,0 +1,12 @@
+
+type String = string
+
+fn (s String) my_upper() string {
+	return s.to_upper()
+}
+
+fn main(){
+
+	mut str := String('abc')
+	println(str.my_upper())
+}
\ No newline at end of file
diff --git a/15_enums/types_declarations.v b/15_enums/types_declarations.v
deleted file mode 100644
index e69de29..0000000
diff --git a/16_interfaces/casting.v b/16_interfaces/casting.v
new file mode 100644
index 0000000..7b4c443
--- /dev/null
+++ b/16_interfaces/casting.v
@@ -0,0 +1,41 @@
+
+
+struct Dog{
+	breed string
+	speak() string
+}
+
+fn (d Dog) speak() string {
+	println('Woof')
+}
+
+
+struct Cat{
+	breed string
+	speak() string
+}
+
+fn (c Cat) speak() string{
+	println('Meow')
+}
+
+interface Something{}
+
+
+fn announce(s Something){
+	if s is Dog {
+		println('a ${s.breed] dog')
+	}else if s is Cat{
+		println('a cat speaks ${s.speak()}')
+	}else {
+		println('something else')
+	}
+}
+
+fn main(){
+	dog := Dog{'Leonberger'}
+	cat := Cat{'Siamese'}
+
+	announce(dog)
+	announce(cat)
+}
\ No newline at end of file
diff --git a/16_interfaces/interfaces.v b/16_interfaces/interfaces.v
new file mode 100644
index 0000000..4f173de
--- /dev/null
+++ b/16_interfaces/interfaces.v
@@ -0,0 +1,26 @@
+
+
+interface Foo{
+	write(string) string
+}
+
+interface Bar{
+mut:
+	write(string) string
+}
+
+struct MyStruct{}
+
+fn (s MyStruct) write(a string) string{
+	return a
+}
+
+fn main(){
+	s1 := MyStruct{}
+
+	fn1(s1)
+}
+
+fn fn1(s Foo){
+	println(s.write('Foo'))
+}
\ No newline at end of file
diff --git a/16_interfaces/main.v b/16_interfaces/main.v
new file mode 100644
index 0000000..267e630
--- /dev/null
+++ b/16_interfaces/main.v
@@ -0,0 +1,34 @@
+struct Dog{
+	breed string
+}
+
+fn (d Dog) speak() string{
+	return 'woof'
+}
+
+struct Cat{
+	breed string
+}
+
+fn (c Cat) speak() string{
+	return 'meow'
+}
+
+interface Speaker{
+	breed string
+	speak() string
+}
+
+fn main(){
+	dog := Dog{'Leonberger'}
+	cat := Cat{'Siamese'}
+
+	mut arr := []Speaker{}
+
+	arr << dog
+	arr << cat
+
+	for item in arr{
+		println('a ${item.breed} says: ${item.speak()}')
+	}
+}
\ No newline at end of file