diff --git a/src/lexer.c b/src/lexer.c
index e7d0a66..83d6967 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -87,6 +87,20 @@ add_token (enum token_type type, struct lexer *l)
 	free (lexeme);
 }
 
+_Bool
+s_eq (const char *s1, const char *s2)
+{
+	if (!s1 || !s2)
+		return 0;
+
+	size_t len1 = strlen (s1);
+	size_t len2 = strlen (s2);
+	if (len1 != len2)
+		return 0;
+
+	return strncmp (s1, s2, len1) == 0;
+}
+
 void
 handle_number (struct lexer *l)
 {
@@ -144,7 +158,43 @@ handle_identifier (struct lexer *l)
 	while (isalnum (peek (l)) || peek (l) == '_')
 		advance (l);
 
-	add_token (TOK_IDENTIFIER, l);
+	char *slice = buffer_slice (l->start, l->cur, l->source);
+	if (s_eq (slice, "if"))
+		add_token (TOK_IF, l);
+	else if (s_eq (slice, "then"))
+		add_token (TOK_THEN, l);
+	else if (s_eq (slice, "else"))
+		add_token (TOK_ELSE, l);
+	else if (s_eq (slice, "true"))
+		add_token (TOK_TRUE, l);
+	else if (s_eq (slice, "false"))
+		add_token (TOK_FALSE, l);
+	else if (s_eq (slice, "and"))
+		add_token (TOK_AND, l);
+	else if (s_eq (slice, "or"))
+		add_token (TOK_OR, l);
+	else if (s_eq (slice, "while"))
+		add_token (TOK_WHILE, l);
+	else if (s_eq (slice, "do"))
+		add_token (TOK_DO, l);
+	else if (s_eq (slice, "for"))
+		add_token (TOK_FOR, l);
+	else if (s_eq (slice, "func"))
+		add_token (TOK_FUNC, l);
+	else if (s_eq (slice, "null"))
+		add_token (TOK_NULL, l);
+	else if (s_eq (slice, "end"))
+		add_token (TOK_END, l);
+	else if (s_eq (slice, "print"))
+		add_token (TOK_PRINT, l);
+	else if (s_eq (slice, "println"))
+		add_token (TOK_PRINTLN, l);
+	else if (s_eq (slice, "ret"))
+		add_token (TOK_RET, l);
+	else
+		add_token (TOK_IDENTIFIER, l);
+
+	free (slice);
 }
 
 /* public functions */
@@ -182,9 +232,6 @@ lexer_lex (struct lexer *l)
 				l->line++;
 			else if (c == ' ' || c == '\t' || c == '\r')
 				continue;
-			else if (c == '#')
-				while (peek (l) != '\n' && !(l->cur >= buffer_length (l->source)))
-					advance (l);
 			/* single-character tokens */
 			else if (c == '(')
 				add_token (TOK_LPAREN, l);
@@ -205,7 +252,18 @@ lexer_lex (struct lexer *l)
 			else if (c == '+')
 				add_token (TOK_PLUS, l);
 			else if (c == '-')
-				add_token (TOK_MINUS, l);
+				{
+					if (match ('-', l))
+						{
+							while (peek (l) != '\n'
+										 && !(l->cur >= buffer_length (l->source)))
+								advance (l);
+
+							continue;
+						}
+
+					add_token (TOK_MINUS, l);
+				}
 			else if (c == '*')
 				add_token (TOK_STAR, l);
 			else if (c == '^')
diff --git a/src/token.h b/src/token.h
index bceaa74..cfb513a 100644
--- a/src/token.h
+++ b/src/token.h
@@ -5,6 +5,7 @@
 
 enum token_type
 {
+	/* single character tokens */
 	TOK_LPAREN,
 	TOK_RPAREN,
 	TOK_LCURLY,
@@ -26,6 +27,7 @@ enum token_type
 	TOK_GT,
 	TOK_LT,
 
+	/* multiple character tokens */
 	TOK_GE,
 	TOK_LE,
 	TOK_NE,
@@ -34,11 +36,13 @@ enum token_type
 	TOK_GTGT,
 	TOK_LTLT,
 
+	/* types */
 	TOK_IDENTIFIER,
 	TOK_STRING,
 	TOK_INTEGER,
 	TOK_FLOAT,
 
+	/* keywords */
 	TOK_IF,
 	TOK_THEN,
 	TOK_ELSE,
diff --git a/src/utils/buffer.c b/src/utils/buffer.c
index 5ccfdc2..1a5138a 100644
--- a/src/utils/buffer.c
+++ b/src/utils/buffer.c
@@ -112,6 +112,39 @@ buffer_read (const char *path, struct buffer *b)
 	return 1;
 }
 
+_Bool
+buffer_eq (const char *s, struct buffer *b)
+{
+	if (!s || !b)
+		return 0;
+
+	size_t slen = strlen (s);
+	if (slen != b->len)
+		return 0;
+
+	return strncmp (s, b->buf, slen) == 0;
+}
+
+char *
+buffer_slice (unsigned int start, unsigned int end, struct buffer *b)
+{
+	if (!b)
+		return NULL;
+
+	if (end > buffer_length (b))
+		return NULL;
+
+	char *str = calloc ((end - start) + 1, sizeof (char));
+	if (!str)
+		return NULL;
+
+	char *bstart = buffer_get (b) + start;
+	strncpy (str, bstart, end - start);
+	str[end - start] = '\0';
+
+	return str;
+}
+
 void
 buffer_free (struct buffer *b)
 {
diff --git a/src/utils/buffer.h b/src/utils/buffer.h
index a8b87e1..7df5641 100644
--- a/src/utils/buffer.h
+++ b/src/utils/buffer.h
@@ -15,6 +15,8 @@ void buffer_append (const char *s, struct buffer *b);
 void buffer_printf (struct buffer *b, const char *fmt, ...);
 char *buffer_get (struct buffer *b);
 _Bool buffer_read (const char *path, struct buffer *b);
+_Bool buffer_eq (const char *s, struct buffer *b);
+char *buffer_slice (unsigned int start, unsigned int end, struct buffer *b);
 void buffer_free (struct buffer *b);
 
 size_t buffer_length (struct buffer *b);
diff --git a/tests/expr.pinky b/tests/expr.pinky
index bf5b0e0..63ec10c 100644
--- a/tests/expr.pinky
+++ b/tests/expr.pinky
@@ -1,2 +1,2 @@
-# Evaluate a simple expression
+-- Evaluate a simple expression
 2 + 3
\ No newline at end of file
diff --git a/tests/multichtokens.pinky b/tests/multichtokens.pinky
index 2dd9d70..e1d2012 100644
--- a/tests/multichtokens.pinky
+++ b/tests/multichtokens.pinky
@@ -1,26 +1,26 @@
-# the equals token:
+-- the equals token:
 ==
 
-# the not equals token:
+-- the not equals token:
 ~=
 
-# the logical not operator
+-- the logical not operator
 ~
 
-# less or equal
+-- less or equal
 <=
 
-# less than
+-- less than
 <
 
-# greater or equal
+-- greater or equal
 >=
 
-# greater than
+-- greater than
 >
 
-# assignment
+-- assignment
 :=
 
-# colon
+-- colon
 :
\ No newline at end of file
diff --git a/tests/program.pinky b/tests/program.pinky
index 9c38c73..2e4a792 100644
--- a/tests/program.pinky
+++ b/tests/program.pinky
@@ -1,4 +1,4 @@
-# initialise variables
+-- initialise variables
 pi := 3.141592
 
 x := 8.23
diff --git a/tests/singletokens.pinky b/tests/singletokens.pinky
index ba48353..784c55c 100644
--- a/tests/singletokens.pinky
+++ b/tests/singletokens.pinky
@@ -1,3 +1,3 @@
-# this file is just to test single character tokens
+-- this file is just to test single character tokens
 { } [ ] ( ) . , +
 - * ^ / ; ? %
\ No newline at end of file