diff --git a/ts/smartexpect.classes.assertion.ts b/ts/smartexpect.classes.assertion.ts
index e0a211e..9430831 100644
--- a/ts/smartexpect.classes.assertion.ts
+++ b/ts/smartexpect.classes.assertion.ts
@@ -100,4 +100,31 @@ export class Assertion {
       }
     });
   }
+
+  public toBeTrue() {
+    return this.runCheck(() => {
+      const result = typeof this.baseReference === 'boolean' && this.baseReference === true;
+      if (!result) {
+        throw new Error(`${this.baseReference} is not true or not of type boolean`);
+      }
+    });
+  }
+
+  public toBeFalse() {
+    return this.runCheck(() => {
+      const result = typeof this.baseReference === 'boolean' && this.baseReference === false;
+      if (!result) {
+        throw new Error(`${this.baseReference} is not false or not of type boolean`);
+      }
+    });
+  }
+
+  public toBeInstanceOf(classArg: any) {
+    return this.runCheck(() => {
+      const result = this.baseReference instanceof classArg;
+      if (!result) {
+        throw new Error(`${this.baseReference} is not an instance of ${classArg}`);
+      }
+    });
+  }
 }