diff --git a/src/objects.ts b/src/objects.ts
index ef6298f..2a671f2 100644
--- a/src/objects.ts
+++ b/src/objects.ts
@@ -27,6 +27,7 @@ function createBook(
   genre: string
 ): Book {
   // write your code here...
+  return {title, author, publishedYear, genre}
 
   return {} as Book; // replace "{} as Book" with what you see is fit
 }
@@ -50,6 +51,7 @@ const book = createBook(
  */
 function printBookTitleAndYear(book: Book): string {
   // write your code here...
+  return book.title + " " + book["publishedYear"]
 
   return ""; // replace empty string with what you see is fit
 }
@@ -66,6 +68,7 @@ function printBookTitleAndYear(book: Book): string {
  */
 function addPageCount(book: Book, pageCount: number): Book {
   // write your code here...
+  book.pageCount = pageCount
 
   return book;
 }
@@ -88,6 +91,7 @@ function addPageCount(book: Book, pageCount: number): Book {
  */
 function addISBN(book: Book, ISBN: string): Book {
   // write your code here...
+  book.ISBN = ISBN
 
   return book;
 }
@@ -110,6 +114,7 @@ function addISBN(book: Book, ISBN: string): Book {
  */
 function updatePublishedYear(book: Book, newYear: number): Book {
   // write your code here...
+  book.publishedYear = newYear
 
   return book;
 }
@@ -135,6 +140,13 @@ 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;
 }