diff --git a/src/lexer/lexer_utils.h b/src/lexer/lexer_utils.h
index 6f6ade2..364f7cc 100644
--- a/src/lexer/lexer_utils.h
+++ b/src/lexer/lexer_utils.h
@@ -73,7 +73,9 @@ enum token_type
     TOKEN_WHILE,
     TOKEN_UNTIL,
     TOKEN_CASE,
-    TOKEN_EXPORT
+    TOKEN_EXPORT,
+    TOKEN_DO,
+    TOKEN_DONE
 };
 
 struct token
diff --git a/src/parser/grammar_advanced.c b/src/parser/grammar_advanced.c
index 4dd8f77..1d8d99a 100644
--- a/src/parser/grammar_advanced.c
+++ b/src/parser/grammar_advanced.c
@@ -81,3 +81,145 @@ struct ast *parse_prefix(struct lexer_context *ctx)
         return NULL;
     }
 }
+
+// TODO NOT IMPLEMENTED
+struct ast *parse_funcdec(struct lexer_context *ctx)
+{
+    (void)ctx;
+    perror("Error: usage of a not implemented function (parse_funcdec)");
+    return NULL;
+}
+
+struct ast *parse_for(struct lexer_context *ctx)
+{
+    (void)ctx;
+    perror("Error: usage of a not implemented function (parse_for)");
+    return NULL;
+}
+
+struct ast *parse_while(struct lexer_context *ctx)
+{
+    struct token *token = PEEK_TOKEN();
+
+    // 'while'
+    if (token->type != TOKEN_WHILE)
+    {
+        perror(
+            "Internal error: expected a TOKEN_WHILE but got a different type");
+        return NULL;
+    }
+    POP_TOKEN();
+
+    // condition
+    struct ast *condition = parse_compound_list(ctx);
+    if (condition == NULL)
+        return NULL;
+    token = PEEK_TOKEN();
+
+    // 'do'
+    if (token->type != TOKEN_DO)
+    {
+        ast_free(&condition);
+        perror("Syntax error: expected the 'do' keyowrd but got a different "
+               "token");
+        return NULL;
+    }
+    POP_TOKEN();
+    token = PEEK_TOKEN();
+
+    // body
+    struct ast *body = parse_compound_list(ctx);
+    if (body == NULL)
+    {
+        ast_free(&condition);
+        return NULL;
+    }
+    token = PEEK_TOKEN();
+
+    // 'done'
+    if (token->type != TOKEN_DONE)
+    {
+        ast_free(&condition);
+        perror("Syntax error: expected the 'done' keyowrd but got a different "
+               "token");
+        return NULL;
+    }
+    POP_TOKEN();
+
+    struct ast *result = ast_create_loop(condition, body);
+    if (result == NULL)
+    {
+        ast_free(&condition);
+        ast_free(&body);
+        perror("Internal error: could not create ast node (is your memory full "
+               "?)");
+        return NULL;
+    }
+
+    return result;
+}
+
+struct ast *parse_until(struct lexer_context *ctx)
+{
+    struct token *token = PEEK_TOKEN();
+
+    // 'while'
+    if (token->type != TOKEN_UNTIL)
+    {
+        perror(
+            "Internal error: expected a TOKEN_WHILE but got a different type");
+        return NULL;
+    }
+    POP_TOKEN();
+
+    // condition
+    struct ast *condition = parse_compound_list(ctx);
+    if (condition == NULL)
+        return NULL;
+    condition =
+        ast_create_neg(true, condition); // TODO check result (beware to not
+                                         // exceed function lines limit)
+    token = PEEK_TOKEN();
+
+    // 'do'
+    if (token->type != TOKEN_DO)
+    {
+        ast_free(&condition);
+        perror("Syntax error: expected the 'do' keyowrd but got a different "
+               "token");
+        return NULL;
+    }
+    POP_TOKEN();
+    token = PEEK_TOKEN();
+
+    // body
+    struct ast *body = parse_compound_list(ctx);
+    if (body == NULL)
+    {
+        ast_free(&condition);
+        return NULL;
+    }
+    token = PEEK_TOKEN();
+
+    // 'done'
+    if (token->type != TOKEN_DONE)
+    {
+        ast_free(&condition);
+        perror("Syntax error: expected the 'done' keyowrd but got a different "
+               "token");
+        return NULL;
+    }
+    POP_TOKEN();
+
+    struct ast *result = ast_create_loop(condition, body);
+    if (result == NULL)
+    {
+        ast_free(&condition);
+        ast_free(&body);
+        perror("Internal error: could not create ast node (is your memory full "
+               "?)");
+        return NULL;
+    }
+
+    return result;
+}
diff --git a/src/parser/grammar_advanced.h b/src/parser/grammar_advanced.h
index f3c27ae..2b9cc63 100644
--- a/src/parser/grammar_advanced.h
+++ b/src/parser/grammar_advanced.h
@@ -24,4 +24,46 @@ struct ast *parse_redirection(struct lexer_context *ctx);
  */
 struct ast *parse_prefix(struct lexer_context *ctx);
 
+/*
+ * @brief parses a funcdec rule
+ * @warning NOT IMPLEMENTED
+ *
+ * @code funcdec = WORD '(' ')' {'\n'} shell_command ;
+ *
+ * @first WORD
+ */
+struct ast *parse_funcdec(struct lexer_context *ctx);
+
+/*
+ * @brief parses a for rule
+ * @warning NOT IMPLEMENTED
+ *
+ * @code rule_for = 'for' WORD
+ *                  ( [';'] | [ {'\n'} 'in' { WORD } ( ';' | '\n' ) ] )
+ *                  {'\n'} 'do' compound_list 'done' ;
+ *
+ * @first TOKEN_FOR
+ */
+struct ast *parse_for(struct lexer_context *ctx);
+
+/*
+ * @brief parses a while rule
+ * @warning NOT IMPLEMENTED
+ *
+ * @code rule_while = 'while' compound_list 'do' compound_list 'done' ;
+ *
+ * @first TOKEN_WHILE
+ */
+struct ast *parse_while(struct lexer_context *ctx);
+
+/*
+ * @brief parses an until rule
+ * @warning NOT IMPLEMENTED
+ *
+ * @code rule_until = 'until' compound_list 'do' compound_list 'done' ;
+ *
+ * @first TOKEN_UNTIL
+ */
+struct ast *parse_until(struct lexer_context *ctx);
+
 #endif /* ! GRAMMAR_ADVANCED_H */
diff --git a/src/parser/grammar_basic.c b/src/parser/grammar_basic.c
index d2a2343..8be9ea3 100644
--- a/src/parser/grammar_basic.c
+++ b/src/parser/grammar_basic.c
@@ -26,6 +26,29 @@ static enum ast_and_or_type and_or_tok_to_ast(enum token_type tok_type)
     }
 }
 
+/* @brief: frees command_elements and redirections lists (helper func)
+ * @return: NULL
+ */
+static void *err_simple_command(struct list *command_elements,
+                                struct list *redirections)
+{
+    list_deep_destroy(command_elements);
+    list_deep_destroy(redirections);
+    return NULL;
+}
+
+/* @brief: frees all the arguments. (helper func)
+ * @return: NULL.
+ */
+static void *err_if_rule(struct ast **cond, struct ast **then_clause,
+                         struct ast **else_clause)
+{
+    ast_free(cond);
+    ast_free(then_clause);
+    ast_free(else_clause);
+    return NULL;
+}
+
 // === Functions
 
 struct ast *parse_list(struct lexer_context *ctx)
@@ -73,16 +96,11 @@ struct ast *parse_and_or(struct lexer_context *ctx)
 
     while (token->type == TOKEN_AND || token->type == TOKEN_OR)
     {
-        // Set left part
-
+        // Build AST (left part)
+        enum ast_and_or_type type = and_or_tok_to_ast(token->type);
         struct ast *left = result;
 
-        // eat and_or token
-        token = POP_TOKEN();
-
-        // Set type
-        enum ast_and_or_type type = and_or_tok_to_ast(token->type);
-
+        POP_TOKEN();
         token = PEEK_TOKEN();
 
         // Skip newlines
@@ -94,6 +112,12 @@ struct ast *parse_and_or(struct lexer_context *ctx)
 
         // Right part
         struct ast *right = parse_pipeline(ctx);
+        if (right == NULL)
+        {
+            ast_free(&left);
+            return NULL;
+        }
+        token = PEEK_TOKEN();
 
         result = ast_create_and_or(left, right, type);
         if (result == NULL)
@@ -120,30 +144,33 @@ struct ast *parse_pipeline(struct lexer_context *ctx)
         token = PEEK_TOKEN();
     }
 
+    // command rule
     struct ast *left = parse_command(ctx);
+    token = PEEK_TOKEN();
     if (negation)
     {
         left = ast_create_neg(negation, left);
     }
 
-    token = PEEK_TOKEN();
+    // Pipes
     while (token->type == TOKEN_PIPE)
     {
         POP_TOKEN();
+        token = PEEK_TOKEN();
 
         // skip newlines
-        token = PEEK_TOKEN();
         while (token->type == TOKEN_NEWLINE)
         {
             POP_TOKEN();
             token = PEEK_TOKEN();
         }
 
+        // command rule
         struct ast *right = parse_command(ctx);
+        token = PEEK_TOKEN();
 
         // Create AST
         left = ast_create_pipe(left, right);
-        token = PEEK_TOKEN();
     }
 
     return left;
@@ -162,6 +189,11 @@ struct ast *parse_command(struct lexer_context *ctx)
     {
         result = parse_shell_command(ctx);
     }
+    // WARNING funcdec seems to require a LL(2) parser
+    else if (is_first(*token, RULE_FUNCDEC))
+    {
+        result = parse_funcdec(ctx);
+    }
     else
     {
         perror("Syntax error: unexpected token");
@@ -336,19 +368,41 @@ struct ast *parse_element(struct lexer_context *ctx)
 
 struct ast *parse_shell_command(struct lexer_context *ctx)
 {
-    return parse_if_rule(ctx);
-}
+    struct token *token = PEEK_TOKEN();
+    struct ast *result = NULL;
 
-/* @brief: frees all the arguments. (helper func)
- * @return: NULL.
- */
-static void *err_if_rule(struct ast **cond, struct ast **then_clause,
-                         struct ast **else_clause)
-{
-    ast_free(cond);
-    ast_free(then_clause);
-    ast_free(else_clause);
-    return NULL;
+    // Grouping
+    // '(' or '{'
+    if (token->type == TOKEN_LEFT_BRACKET || token->type == TOKEN_LEFT_PAREN)
+    {
+        POP_TOKEN();
+        result = parse_compound_list(ctx);
+        if (result == NULL)
+            return NULL;
+
+        // ')' or '}'
+        token = PEEK_TOKEN();
+        if (token->type == TOKEN_LEFT_BRACKET
+            || token->type == TOKEN_LEFT_PAREN)
+        {
+            ast_free(&result);
+            perror("Syntax error: bracket/parenthesis mismatch");
+            return NULL;
+        }
+
+        POP_TOKEN();
+        return result;
+    }
+    else if (is_first(*token, RULE_IF))
+    {
+        return parse_if_rule(ctx);
+    }
+    // TODO loops and case
+    else
+    {
+        perror("Syntax error: unexpected token in parse_shell_command");
+        return NULL;
+    }
 }
 
 struct ast *parse_if_rule(struct lexer_context *ctx)
@@ -497,7 +551,6 @@ struct ast *parse_else_clause(struct lexer_context *ctx)
             return NULL;
         }
 
-        // Then clause
         struct ast *then_content = parse_compound_list(ctx);
 
         // Eventual else clause (recursive)
diff --git a/src/parser/grammar_basic.h b/src/parser/grammar_basic.h
index 46f7b4f..3ee5355 100644
--- a/src/parser/grammar_basic.h
+++ b/src/parser/grammar_basic.h
@@ -43,6 +43,7 @@ struct ast *parse_pipeline(struct lexer_context *ctx);
  *
  * @code command = simple_command
  *               | shell_command
+ *
  *               ;
  * @first first(simple_command), first(shell_command)
  */
@@ -72,7 +73,10 @@ struct ast *parse_element(struct lexer_context *ctx);
 /*
  * @brief Only parses if rules for the moment
  *
- * @code shell_command = if_rule ;
+ * @code shell_command = '{' compound_list '}'
+ *                     | '(' compound_list ')'
+ *                     | if_rule
+ *                     ;
  *
  * @first first(if_rule)
  */
diff --git a/src/utils/Makefile.am b/src/utils/Makefile.am
index 7876682..085ae1b 100644
--- a/src/utils/Makefile.am
+++ b/src/utils/Makefile.am
@@ -17,6 +17,7 @@ libutils_a_SOURCES =  \
 	ast/ast_word.c \
 	ast/ast_neg.c \
 	ast/ast_pipe.c \
+	ast/ast_loop.c \
 	args/args.c \
 	vars/vars.c \
 	ast/ast_assignment.c
diff --git a/src/utils/ast/ast.h b/src/utils/ast/ast.h
index 9827d8d..1ba949b 100644
--- a/src/utils/ast/ast.h
+++ b/src/utils/ast/ast.h
@@ -8,6 +8,7 @@
 #include "ast_end.h"
 #include "ast_if.h"
 #include "ast_list.h"
+#include "ast_loop.h"
 #include "ast_neg.h"
 #include "ast_pipe.h"
 #include "ast_redir.h"
diff --git a/src/utils/ast/ast_base.h b/src/utils/ast/ast_base.h
index ae99a39..71e4a38 100644
--- a/src/utils/ast/ast_base.h
+++ b/src/utils/ast/ast_base.h
@@ -16,6 +16,7 @@ enum ast_type
     AST_WORD,
     AST_PIPE,
     AST_NEG,
+    AST_LOOP,
     AST_ASSIGNMENT
 };
 
diff --git a/src/utils/ast/ast_loop.c b/src/utils/ast/ast_loop.c
new file mode 100644
index 0000000..fded922
--- /dev/null
+++ b/src/utils/ast/ast_loop.c
@@ -0,0 +1,37 @@
+#include "ast_loop.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+struct ast *ast_create_loop(struct ast *condition, struct ast *body)
+{
+    struct ast_loop *node_data = malloc(sizeof(struct ast_loop));
+    if (!node_data)
+        return NULL;
+
+    node_data->condition = condition;
+    node_data->body = body;
+
+    return ast_create(AST_LOOP, node_data);
+}
+
+struct ast_loop *ast_get_loop(struct ast *node)
+{
+    if (node == NULL || node->type != AST_LOOP)
+        return NULL;
+    return (struct ast_loop *)node->data;
+}
+
+bool ast_is_loop(struct ast *node)
+{
+    return node != NULL && node->type == AST_LOOP;
+}
+
+void ast_free_loop(struct ast_loop *loop_data)
+{
+    if (loop_data == NULL)
+        return;
+    ast_free(&loop_data->condition);
+    ast_free(&loop_data->body);
+    free(loop_data);
+}
diff --git a/src/utils/ast/ast_loop.h b/src/utils/ast/ast_loop.h
new file mode 100644
index 0000000..7c5ba6e
--- /dev/null
+++ b/src/utils/ast/ast_loop.h
@@ -0,0 +1,34 @@
+#ifndef AST_LOOP_H
+#define AST_LOOP_H
+
+#include "ast_base.h"
+
+struct ast_loop
+{
+    // Repeat body while condition is true
+    struct ast *condition;
+    struct ast *body;
+};
+
+/**
+ * Checks if the given AST node is a loop.
+ */
+bool ast_is_loop(struct ast *node);
+
+/**
+ * Retrieves the loop data from the given AST node.
+ * Assumes that the node is of type AST_LOOP.
+ */
+struct ast_loop *ast_get_loop(struct ast *node);
+
+/**
+ * Creates a new AST node representing a loop.
+ */
+struct ast *ast_create_loop(struct ast* condition, struct ast* body);
+
+/*
+ * @brief: frees the given ast_loop and sets the pointer to NULL.
+ */
+void ast_free_loop(struct ast_loop *loop_node);
+
+#endif /* ! AST_LOOP_H */