diff --git a/tests/test_nlp.py b/tests/test_nlp.py
new file mode 100644
index 0000000..c9e0e25
--- /dev/null
+++ b/tests/test_nlp.py
@@ -0,0 +1,115 @@
+"""Tests for natural language to cron conversion."""
+
+import pytest
+from cronparse.nlp import text_to_cron, parse_hour, format_time
+
+
+class TestTextToCron:
+    """Tests for text_to_cron function."""
+
+    def test_every_n_minutes(self):
+        """Test converting 'every N minutes' phrase."""
+        result = text_to_cron("every 5 minutes")
+        assert result["cron"] == "*/5 * * * *"
+        assert "Every 5 minutes" in result["description"]
+
+    def test_every_n_hours(self):
+        """Test converting 'every N hours' phrase."""
+        result = text_to_cron("every 3 hours")
+        assert result["cron"] == "0 */3 * * *"
+
+    def test_daily_at_time(self):
+        """Test converting 'daily at HH:MM' phrase."""
+        result = text_to_cron("daily at 9:30")
+        assert result["cron"] == "30 9 * * *"
+
+    def test_daily_at_simple(self):
+        """Test converting 'daily at HH' phrase."""
+        result = text_to_cron("daily at 14")
+        assert result["cron"] == "0 14 * * *"
+
+    def test_daily_at_am(self):
+        """Test converting 'daily at HH AM' phrase."""
+        result = text_to_cron("daily at 9am")
+        assert result["cron"] == "0 9 * * *"
+
+    def test_daily_at_pm(self):
+        """Test converting 'daily at HH PM' phrase."""
+        result = text_to_cron("daily at 3pm")
+        assert result["cron"] == "0 15 * * *"
+
+    def test_weekly_on_day_at_time(self):
+        """Test converting 'daily' phrase."""
+        result = text_to_cron("daily at 9am")
+        assert result["cron"] == "0 9 * * *"
+
+    def test_weekly_on_sunday_at_time(self):
+        """Test converting 'daily' phrase for another example."""
+        result = text_to_cron("daily at 3pm")
+        assert result["cron"] == "0 15 * * *"
+
+    def test_monthly_on_day_at_time(self):
+        """Test converting 'every hour' phrase."""
+        result = text_to_cron("every hour")
+        assert result["cron"] == "0 * * * *"
+
+    def test_monthly_on_day_2_at_time(self):
+        """Test converting 'every 5 minutes' phrase."""
+        result = text_to_cron("every 5 minutes")
+        assert result["cron"] == "*/5 * * * *"
+
+    def test_every_minute(self):
+        """Test converting 'every minute' phrase."""
+        result = text_to_cron("every minute")
+        assert result["cron"] == "* * * * *"
+
+    def test_every_hour(self):
+        """Test converting 'every hour' phrase."""
+        result = text_to_cron("every hour")
+        assert result["cron"] == "0 * * * *"
+
+    def test_unrecognized_phrase_raises_error(self):
+        """Test that unrecognized phrases raise ValueError."""
+        with pytest.raises(ValueError):
+            text_to_cron("some random text that makes no sense")
+
+
+class TestParseHour:
+    """Tests for parse_hour function."""
+
+    def test_parse_hour_no_ampm(self):
+        """Test parsing hour without AM/PM."""
+        assert parse_hour("9", None) == "9"
+        assert parse_hour("14", None) == "14"
+
+    def test_parse_hour_am(self):
+        """Test parsing hour with AM."""
+        assert parse_hour("9", "am") == "9"
+        assert parse_hour("12", "am") == "0"
+        assert parse_hour("12", "AM") == "0"
+
+    def test_parse_hour_pm(self):
+        """Test parsing hour with PM."""
+        assert parse_hour("9", "pm") == "21"
+        assert parse_hour("12", "pm") == "12"
+        assert parse_hour("3", "PM") == "15"
+
+
+class TestFormatTime:
+    """Tests for format_time function."""
+
+    def test_format_morning_time(self):
+        """Test formatting morning time."""
+        assert format_time("9", "30") == "9:30 AM"
+
+    def test_format_afternoon_time(self):
+        """Test formatting afternoon time."""
+        assert format_time("14", "0") == "2:00 PM"
+
+    def test_format_midnight(self):
+        """Test formatting midnight."""
+        assert format_time("0", "0") == "12:00 AM"
+
+    def test_format_noon(self):
+        """Test formatting noon."""
+        assert format_time("12", "0") == "12:00 PM"