diff --git a/src/lexer/highlighter.ts b/src/lexer/highlighter.ts
index efcdba7..aeb2d44 100644
--- a/src/lexer/highlighter.ts
+++ b/src/lexer/highlighter.ts
@@ -191,10 +191,10 @@ function process_token_value_and_end(value: string, token_type: TokenType, first
 }
 
 function translate_token_type(tt: TokenType, value: string): string {
-    const keywords = ["throws", "extends", "constructor", "case", "static", "const",
-        "enum", "union", "loop", "use", "break", "catch", "continue", "as", "do",
-        "finally", "for", "fun", "in", "fn", "nil", "return", "throw",
-        "try", "while", "type", "match", "with", "of", "abstract", "class", "interface",
+    const keywords = ["throws", "extends", "constructor", "static", "const",
+        "enum", "union", "use", "break", "catch", "continue", "as", "do",
+        "finally", "fun", "fn", "nil", "return", "throw",
+        "try", "type", "with", "of", "abstract", "class", "interface",
         "private", "protected", "pub", "override", "open", "init", "val", "var", "mut", "clone"];
 
     switch (tt) {
@@ -222,6 +222,12 @@ function translate_token_type(tt: TokenType, value: string): string {
         case "FUN":
         case "IF":
         case "ELSE":
+        case "FOR":
+        case "IN":
+        case "WHILE":
+        case "LOOP":
+        case "MATCH":
+        case "CASE":
             return "keyword";
         default:
             return tt;
diff --git a/src/lexer/types.ts b/src/lexer/types.ts
index 7837b5c..54f0d55 100644
--- a/src/lexer/types.ts
+++ b/src/lexer/types.ts
@@ -11,30 +11,37 @@ export interface Token {
 }
 
 export type TokenType =
-    "Identifier" |
-    "Datatype" |
-    "Int" |
-    "Float" |
-    "String" |
-    "Operator" |
-    "LeftParen" |
-    "RightParen" |
-    "LeftBracket" |
-    "RightBracket" |
-    "LeftBrace" |
-    "RightBrace" |
-    "NewLine" |
-    "Comment" |
-    "MultilineComment" |
-    "Comma" |
-    "INDENT" |
-    "DEDENT" |
-    "VAL" |
-    "VAR" |
-    "EOF" |
-    "FUN" |
-    "IF" |
-    "ELSE";
+    | "Identifier"
+    | "Datatype"
+    | "Int"
+    | "Float"
+    | "String"
+    | "Operator"
+    | "LeftParen"
+    | "RightParen"
+    | "LeftBracket"
+    | "RightBracket"
+    | "LeftBrace"
+    | "RightBrace"
+    | "NewLine"
+    | "Comment"
+    | "MultilineComment"
+    | "Comma"
+    | "INDENT"
+    | "DEDENT"
+    | "VAL"
+    | "VAR"
+    | "EOF"
+    | "FUN"
+    | "IF"
+    | "ELSE"
+    | "ELSE"
+    | "FOR"
+    | "IN"
+    | "WHILE"
+    | "MATCH"
+    | "CASE"
+    ;
 
 export interface Err {
     Lex?: LexError
diff --git a/src/pages/learn/basics/datatypes.mdx b/src/pages/learn/basics/datatypes.mdx
index 6cef198..45ea586 100644
--- a/src/pages/learn/basics/datatypes.mdx
+++ b/src/pages/learn/basics/datatypes.mdx
@@ -60,6 +60,16 @@ Strings have interpolation with `{}`.
 print("Hello, {name}")      // Hello, Rose
 `} />
 
+Unlike PHP, THP strings are concatenated with `++`, not with `.`.
+This new operator implicitly converts any operator into a string.
+
+<Code thpcode={`
+val name = "John" ++ " " ++ "Doe"
+val greeting = "My name is " ++ name ++ " and I'm " ++ 32 ++ " years old"
+`} />
+
+The plus operator `+` is reserved for numbers.
+
 
 ## Bool
 
diff --git a/src/pages/learn/basics/operators.mdx b/src/pages/learn/basics/operators.mdx
index 32e47cf..96cf380 100644
--- a/src/pages/learn/basics/operators.mdx
+++ b/src/pages/learn/basics/operators.mdx
@@ -71,18 +71,16 @@ number xand 1
 
 ## Strings
 
-TBD.
-
-Strings **do not use `.`** for concatenation. They use `+`.
+Strings **do not use `.`** for concatenation. They use `++`.
 
 <Code thpcode={`
-"Hello " + "world."
+"Hello " ++ "world."
 `} />
 
-However, the plus operator `+` does not implicitly convert types.
+This new operator **implicitly converts** types to string
 
 <Code thpcode={`
-"Hello " + 322      // This is an error
+"Hello " ++ 322      // 322 will be converted to "322"
 `} />
 
 
diff --git a/src/pages/learn/flow-control/loops.mdx b/src/pages/learn/flow-control/loops.mdx
index 3dd53a7..7c1c88b 100644
--- a/src/pages/learn/flow-control/loops.mdx
+++ b/src/pages/learn/flow-control/loops.mdx
@@ -8,14 +8,16 @@ import Code from "../../../components/Code.astro"
 
 ## For loop
 
-This is simmilar to PHP's `foreach`. There is no equivalent to PHP's `for`.
+THP loops are similar to PHP's `foreach`. There is no equivalent to PHP's `for`.
 
 Braces are required.
 
+### Loop over values
+
 <Code thpcode={`
 val numbers = [0, 1, 2, 3]
 
-for #(index, number) in numbers
+for number in numbers
 {
     print(number)
 }
@@ -28,14 +30,38 @@ val dict = .{
     cherries: 3,
 }
 
-for #(key, value) in dict
+for value in dict
+{
+    print("{value}")
+}
+`} />
+
+
+### Loop over keys and values
+
+<Code thpcode={`
+val numbers = [0, 1, 2, 3]
+
+for index, number in numbers
+{
+    print("{index} : {number}")
+}
+`} />
+
+<Code thpcode={`
+val dict = .{
+    apple: 10,
+    banana: 7,
+    cherries: 3,
+}
+
+for key, value in dict
 {
     print("{key} => {value}")
 }
 `} />
 
 
-
 ## While loop
 
 <Code thpcode={`
@@ -50,25 +76,10 @@ while index < colors.size()
 `} />
 
 
-## Infinite loop
-
-Instead of doing `while true {}` use `loop`.
-
-<Code thpcode={`
-loop
-{
-    print("looping")
-
-    if condition
-    {
-        break
-    }
-}
-`} />
-
-
 ## Labelled loops
 
+TBD
+
 You can give labels to loops, allowing you to `break` and `continue` in nested loops.
 
 <Code thpcode={`