diff --git a/src/challenge.ts b/src/challenge.ts
index d697960..f64fa08 100644
--- a/src/challenge.ts
+++ b/src/challenge.ts
@@ -39,7 +39,10 @@ function addReview(
   comment: string
 ): ReviewedBook {
   // write your code here...
-
+  if (!book.reviews) {
+    book.reviews = [];
+  }
+  book.reviews?.push({ reviewer, comment });
   return book;
 }
 
diff --git a/src/objects.ts b/src/objects.ts
index ef6298f..b6cdb66 100644
--- a/src/objects.ts
+++ b/src/objects.ts
@@ -1,3 +1,5 @@
+import { B } from "@faker-js/faker/dist/airline-BcEu2nRk";
+
 // don't change this interface
 interface Book {
   title: string;
@@ -28,7 +30,7 @@ function createBook(
 ): Book {
   // write your code here...
 
-  return {} as Book; // replace "{} as Book" with what you see is fit
+  return { title, author, publishedYear, genre } as Book;
 }
 
 // DO NOT CHANGE THE LINE OF CODE BELOW (you can use it for testing your code)
@@ -50,8 +52,7 @@ const book = createBook(
  */
 function printBookTitleAndYear(book: Book): string {
   // write your code here...
-
-  return ""; // replace empty string with what you see is fit
+  return `${book.title} ${book["publishedYear"]}`;
 }
 
 /**
@@ -66,7 +67,7 @@ function printBookTitleAndYear(book: Book): string {
  */
 function addPageCount(book: Book, pageCount: number): Book {
   // write your code here...
-
+  book.pageCount = pageCount;
   return book;
 }
 
@@ -88,7 +89,7 @@ function addPageCount(book: Book, pageCount: number): Book {
  */
 function addISBN(book: Book, ISBN: string): Book {
   // write your code here...
-
+  book.ISBN = ISBN;
   return book;
 }
 
@@ -110,7 +111,7 @@ function addISBN(book: Book, ISBN: string): Book {
  */
 function updatePublishedYear(book: Book, newYear: number): Book {
   // write your code here...
-
+  book.publishedYear = newYear;
   return book;
 }
 
@@ -135,8 +136,19 @@ function updatePublishedYear(book: Book, newYear: number): Book {
  */
 function addSecondAuthor(book: Book, additionalAuthor: string): Book {
   // write your code here...
-
+  if (Array.isArray(book.author)) {
+    book.author.push(additionalAuthor);
+  } else {
+    book.author = [book.author, additionalAuthor];
+  }
   return book;
+
+  // return {
+  //   ...book,
+  //   author: Array.isArray(book.author)
+  //     ? [...book.author, additionalAuthor]
+  //     : [book.author, additionalAuthor],
+  // };
 }
 
 export {