diff --git a/c03/ex02.c b/c03/ex02.c
new file mode 100644
index 0000000..d42b7fd
--- /dev/null
+++ b/c03/ex02.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ex02.c                                             :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: achubuko <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/11/30 19:58:12 by achubuko          #+#    #+#             */
+/*   Updated: 2023/11/30 21:14:32 by achubuko         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+#include <tests.h>
+#define TESTS_RETURN_PRINTF "%p"
+
+char *ft_strcat(char *dest, char *src);
+
+int	main(void)
+{
+	TESTS_SEED(char);
+
+	printf("initial strings:\n");
+	dump(s, TEST_SOURCE_LENGHT);
+	dump(d, TEST_DESTINATION_LENGHT);
+
+	r1 = strcat(d1, s1);
+	r2 = ft_strcat(d2, s2);
+	TESTS_SYNOPSIS("strcat(d, s)");
+
+	r1 = strcat(d1, s1);
+	r2 = ft_strcat(d2, s2);
+	TESTS_SYNOPSIS("strcat(d, s)");
+
+	r1 = strcat(s1, d1);
+	r2 = ft_strcat(s2, d2);
+	TESTS_SYNOPSIS("strcat(s, d)");
+}
diff --git a/c03/ex03.c b/c03/ex03.c
new file mode 100644
index 0000000..62cba85
--- /dev/null
+++ b/c03/ex03.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ex02.c                                             :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: achubuko <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/11/30 19:58:12 by achubuko          #+#    #+#             */
+/*   Updated: 2023/11/30 21:32:12 by achubuko         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+#include <tests.h>
+#define TESTS_RETURN_PRINTF "%p"
+
+char *ft_strncat(char *dest, char *src, unsigned int nb);
+
+int	main(void)
+{
+	TESTS_SEED(char);
+
+	printf("initial strings:\n");
+	dump(s, TEST_SOURCE_LENGHT);
+	dump(d, TEST_DESTINATION_LENGHT);
+
+	r1 = strncat(d1, s1, 6);
+	r2 = ft_strncat(d2, s2, 6);
+	TESTS_SYNOPSIS("strncat(d, s, 6)");
+
+	r1 = strncat(d1, s1, 20);
+	r2 = ft_strncat(d2, s2, 20);
+	TESTS_SYNOPSIS("strncat(d, s, 20)");
+
+	r1 = strncat(s1, d1, 5);
+	r2 = ft_strncat(s2, d2, 5);
+	TESTS_SYNOPSIS("strncat(s, d, 5)");
+}