There are two ways to count words in Microsoft Word:
1st - Using the status bar
The status bar is a bar at the bottom left of the Word window. It shows information about the document, such as the number of pages, words, paragraphs and lines. By default, when a document is open, it will already be showing the number of words.
In addition to the number of words, in Microsoft Word you can also know the number of:
To see all this information, simply click on the number of words and a dialog box with all the information will open.
2nd - Using the menu options
If you do not find the bar in the bottom menu of the screen, access the functionality by navigating to the menu Review, option Word Count.
Microsoft Word also allows you to count only part of the text, to do this, simply select the desired part and click on Word Count.
When you click on the button to check repeated words, a ranking will be created with the position and number of words used in your text, so you can identify the repetition of words, for example, if you copy this excerpt of text, place the field and ask to check , you will identify that the most used word was "the", used 6 times.
Notepad++, click on the menu View, option: Summary....
Google Docs, click on the menu Tools, opção: Word count.