diff --git a/labs/03/lexer.l b/labs/03/lexer.l
new file mode 100644
index 0000000..26a4eb7
--- /dev/null
+++ b/labs/03/lexer.l
@@ -0,0 +1,16 @@
+%{
+#include "y.tab.h"
+%}
+
+%%
+"the"|"a"                   {return ARTICLE; }
+"boy"|"girl"|"flower"       {return NOUN; }
+"touches"|"likes"|"sees"    {return VERB; }
+"with"                      {return PREPOS; }
+\n                          {return ENDLINE; }
+[ \t]                       ; /*Sin espacios vacios*/
+%%
+
+int yywrap(void) {
+    return 1;
+}
diff --git a/labs/03/parser.y b/labs/03/parser.y
new file mode 100644
index 0000000..c6d8783
--- /dev/null
+++ b/labs/03/parser.y
@@ -0,0 +1,29 @@
+%{
+#include <stdio.h>
+%}
+
+%token ARTICLE NOUN VERB PREPOS ENDLINE 
+
+%%
+sentence : noun_phrase verb_phrase ENDLINE               {printf("PASS\n");}
+         | noun_phrase verb_phrase prep_phrase ENDLINE   {printf("PASS\n");}
+         ;
+
+noun_phrase : cmplx_noun                         { }
+            | cmplx_noun prep_phrase             { }
+            ;
+
+verb_phrase : cmplx_verb                         { }
+            | cmplx_verb prep_phrase             { }
+            ;
+
+prep_phrase : PREPOS cmplx_noun                  { }
+            ;
+
+cmplx_noun : ARTICLE NOUN                        { }
+           ;
+
+cmplx_verb : VERB                                { }
+           | VERB noun_phrase                    { }
+           ;
+%%
diff --git a/labs/03/test.txt b/labs/03/test.txt
new file mode 100644
index 0000000..b464089
--- /dev/null
+++ b/labs/03/test.txt
@@ -0,0 +1,4 @@
+a boy sees
+the boy sees a flower
+a girl with a flower likes the boy
+a flower sees a flower