Till this time changing language in Google products is really difficult because different products has different ways of changing language and you actually can’t change language for all different products at one go, you will have to do it separately. So here is the process for different products

A. Google search engine
1. Go to Google.co.in
2. select language just below the Google name

Or
1. Go to Google.co.in
2. Select the settings, check at the right bottom corner
3. Select search settings
4. Go to language
5. Select your language
6. Save it

B. Chrome
1. Open chrome
2. Click on the button which is at the extreme top extreme right corner
3. Go to settings
4. Go to show advanced settings
5. Select language and input settings under language
6. Click on add
7. Select language
8. Drag to change order
9. Click on done

C. Youtube
1. Go to Youtube.com
2. Go to extreme bottom
3. Click on English
4. Select language

D. Youtube
1. Open Youtube.com
2. Click on the settings icon on the top right corner
3. Click on Youtube settings
4. Select Email from the left hand list
5. Go to extreme bottom, change language

E. Gmail
1. Open your mail
2. Click on the settings icon
3. Go to settings
4. Change language from the very first list of the very first tab
5. You can change language for other google products as well but this one doesn’t work properly all the time

F. Android UI
1. Go to settings
2. Go to Language and Inputs
3. Touch language
4. Select your language

G. Android Input methods
1. Go to settings
2. Go to Language and Inputs
3. Go to Keyboard and Input methods
4. Check “………. Input method” and tap ok (……. = your language)
5. Choose it as your default input method
6. To change it, check on the globe icon to cycle through the chosen language

Hope that helps, let us know your inputs. Keep Googling, in YOUR LANGUAGE.