String[] words = sentence.split(" ");
String[] reversedWords = ArrayUtils.reverse(words);
String reversedSentence = StringUtils.join(reversedWords, " ");

(using ArrayUtils and StringUtils from commons-lang, but these are easy methods to write - just a few loops)

Here is a suggestion:

• write a method that reverses a string:

  private static String reverse(String s) { ... }
  

• then in your main method, call it when necessary:

  if (str.length() >= 5) str = reverse(str);
  

• you then need to put the words back together, presumably into the reversedSentence string:

  reversedSentence += str + " "; //you will have an extra space at the end
  

Side notes:

• using a StringBuilder may prove more efficient than string concatenation for longer sentences.
• you could put all the words back into a List<String> within the loop and call reversedSentence = String.join(" ", list) after the loop
• reversing a string can be done in one line - you should find numerous related Q&As on stackoverflow.

I see a few problems all in your first method: 1. In your first method you are returning words, which is just an array split, that's why you are getting the original output, because that's what you are returning. After your split, you can instantiate a new String to hold the reversed words with a =+. After each call to the second reversedWord method, you can add to the string an empty space " ". However this will also add a space after the last word of the sentence, so to make it even better I suggest you check if you are working on the last word, if not you add the space, if so, then you don't. Your second method is fine. Here is the working code: ```java public class Solution { public static void main(String[] args) { System.out.println(reverseWords("My name is Pedro")); } public static String reverseWords(String s) { String[] words = s.split(" "); String ss = ""; for(String word : words){ ss += reverseWord(word); ss += " "; } return String.join(" ", ss); } public static String reverseWord(String s){ char[] letters = s.toCharArray(); s=""; for(int i=letters.length-1;i>=0;i--){ s=s + letters[i]; } return s; } } ``` I also suggest you rename your methods better to signify what they are really doing. My variably ss is also very badly named.