Google services work in over 130 languages, so they can reach all users. You can change Gmail's default language from its settings or change your Google account's default language from your account settings. The steps to follow will allow you to change the language of Gmail on a computer.
Steps
Method 1 of 2: Change the default language of Gmail

Step 1. Open Gmail in the browser of your choice

Step 2. Sign in to Gmail, if you haven't already
For this, you must have a pre-existing Gmail account.

Step 3. Click on the gear icon below your profile icon
This is in the upper right corner of the screen.

Step 4. Click Settings from the drop-down menu
The option Settings is the third option from the bottom of the menu.

Step 5. Find the Language section
This is the first section in the tab General menu Settings.

Step 6. Click the bar labeled Gmail Display Language
This is the first bar that appears on the page. The language you are using will be displayed in this bar.

Step 7. Select your preferred language from the drop-down menu
Make sure you choose the exact language you want to use, before continuing.

Step 8. Click Save Changes to save the changes
You will find this option at the bottom of the page. The default language for your Gmail account is now changed. You will need to refresh your browser to see the changes, if they do not appear yet.
Method 2 of 2: Change the default language of your Google account

Step 1. Open a browser of your choice

Step 2. Access your account
Click on this link.
- You can also access your Google account in the Chrome browser by clicking on the icon of the three horizontal lines in the toolbar, then on New tab and selecting My account.

Step 3. Sign in to your Google account, if you haven't already
Sign in using your Gmail address and password.

Step 4. Click Language & Input Tools in the Account Preferences section
You will access the menu Language and input tools.

Step 5. In the Language and input tools window, select the Language option
You will access the menu Tongue.

Step 6. Click on the pencil icon next to the language in use
This will display a list of all the languages supported by Google.
- You can also click on the option Add another language at the bottom of the screen to add a secondary language you understand.

Step 7. Select your preferred language, then click OK to save the changes
The default language of your Google account is now changed. If the changes do not appear yet, please refresh your browser to reflect the changes.