diff --git a/textgrid/interval_test.go b/textgrid/interval_test.go
new file mode 100644
index 0000000..294626b
--- /dev/null
+++ b/textgrid/interval_test.go
@@ -0,0 +1,21 @@
+package textgrid
+
+import "testing"
+
+func TestCreatingInterval(t *testing.T) {
+	interval := Interval{xmin: 0.0, xmax: 1.0, text: "test"}
+
+	if interval.xmin != 0.0 {
+		t.Errorf("Expected 0.0, got %f", interval.xmin)
+	}
+	if interval.xmax != 1.0 {
+		t.Errorf("Expected 1.0, got %f", interval.xmax)
+	}
+	if interval.text != "test" {
+		t.Errorf("Expected 'test', got %s", interval.text)
+	}
+
+	if !t.Failed() {
+		t.Logf("interval created successfully")
+	}
+}
diff --git a/textgrid/point_test.go b/textgrid/point_test.go
new file mode 100644
index 0000000..b861e48
--- /dev/null
+++ b/textgrid/point_test.go
@@ -0,0 +1,18 @@
+package textgrid
+
+import "testing"
+
+func TestCreatingPoint(t *testing.T) {
+	point := Point{mark: "point", value: 10.0}
+
+	if point.value != 10.0 {
+		t.Errorf("Expected 10.0, got %f", point.value)
+	}
+	if point.mark != "point" {
+		t.Errorf("Expected 'mark', got %s", point.mark)
+	}
+
+	if !t.Failed() {
+		t.Logf("point created successfully")
+	}
+}
diff --git a/textgrid/tiers_test.go b/textgrid/tiers_test.go
new file mode 100644
index 0000000..4838030
--- /dev/null
+++ b/textgrid/tiers_test.go
@@ -0,0 +1,82 @@
+package textgrid
+
+import "testing"
+
+func TestCreatingIntervalTier(t *testing.T) {
+	intervals := []Interval{
+		{0.0, 1.0, "test1"},
+		{1.0, 2.0, "test2"},
+		{2.0, 3.0, "test3"},
+	}
+
+	tier := IntervalTier{name: "TestTier", xmin: 0.0, xmax: 3.0, intervals: intervals}
+
+	if tier.name != "TestTier" {
+		t.Errorf("Expected 'TestTier', got %s", tier.name)
+	}
+	if tier.xmin != 0.0 {
+		t.Errorf("Expected 0.0, got %f", tier.xmin)
+	}
+	if tier.xmax != 3.0 {
+		t.Errorf("Expected 3.0, got %f", tier.xmax)
+	}
+	if len(tier.intervals) != 3 {
+		t.Errorf("Expected 3 intervals, got %d", len(tier.intervals))
+	}
+
+	for _, interval := range tier.intervals {
+		if interval.text != "test1" && interval.text != "test2" && interval.text != "test3" {
+			t.Errorf("Expected 'test1', 'test2', or 'test3', got %s", interval.text)
+		}
+
+		if interval.xmin != 0.0 && interval.xmin != 1.0 && interval.xmin != 2.0 {
+			t.Errorf("Expected 0.0, 1.0, or 2.0, got %f", interval.xmin)
+		}
+
+		if interval.xmax != 1.0 && interval.xmax != 2.0 && interval.xmax != 3.0 {
+			t.Errorf("Expected 1.0, 2.0, or 3.0, got %f", interval.xmax)
+		}
+	}
+
+	if !t.Failed() {
+		t.Logf("interval tier created successfully")
+	}
+}
+
+func TestSettingIntervals(t *testing.T) {
+	intervals := []Interval{
+		{0.0, 1.0, "test1"},
+		{1.0, 2.0, "test2"},
+		{2.0, 3.0, "test3"},
+	}
+
+	tier := IntervalTier{name: "TestTier", xmin: 0.0, xmax: 3.0}
+
+	err := tier.SetIntervals(intervals)
+
+	if err != nil {
+		t.Errorf("Expected nil, got %s", err)
+	}
+
+	if len(tier.intervals) != 3 {
+		t.Errorf("Expected 3 intervals, got %d", len(tier.intervals))
+	}
+
+	for _, interval := range tier.intervals {
+		if interval.text != "test1" && interval.text != "test2" && interval.text != "test3" {
+			t.Errorf("Expected 'test1', 'test2', or 'test3', got %s", interval.text)
+		}
+
+		if interval.xmin != 0.0 && interval.xmin != 1.0 && interval.xmin != 2.0 {
+			t.Errorf("Expected 0.0, 1.0, or 2.0, got %f", interval.xmin)
+		}
+
+		if interval.xmax != 1.0 && interval.xmax != 2.0 && interval.xmax != 3.0 {
+			t.Errorf("Expected 1.0, 2.0, or 3.0, got %f", interval.xmax)
+		}
+	}
+
+	if !t.Failed() {
+		t.Logf("intervals set successfully")
+	}
+}