diff --git a/ts/smartexpect.classes.assertion.ts b/ts/smartexpect.classes.assertion.ts
index 492e870..34fbd1b 100644
--- a/ts/smartexpect.classes.assertion.ts
+++ b/ts/smartexpect.classes.assertion.ts
@@ -205,6 +205,30 @@ export class Assertion {
     });
   }
 
+  public toStartWith(itemArg: any) {
+    return this.runCheck(() => {
+      const testObject = this.getObjectToTestReference();
+      const result =
+        typeof testObject === 'string' &&
+        testObject.startsWith(itemArg);
+      if (!result) {
+        throw new Error(`${this.baseReference} with drill down ${this.propertyDrillDown} is not contain ${itemArg}`);
+      }
+    });
+  }
+
+  public toEndWith(itemArg: any) {
+    return this.runCheck(() => {
+      const testObject = this.getObjectToTestReference();
+      const result =
+        typeof testObject === 'string' &&
+        testObject.endsWith(itemArg);
+      if (!result) {
+        throw new Error(`${this.baseReference} with drill down ${this.propertyDrillDown} is not contain ${itemArg}`);
+      }
+    });
+  }
+
   public property(propertyNameArg: string) {
     this.propertyDrillDown.push(propertyNameArg);
     return this;