How do I enable the autotranslate feature using Gboard?

[AC Question]

I am using a Samsung Note 4. After reading about the Gboard (Google Key Board) app in the latest Androidcentral message, I decided to install it. I like it! But, I can't figure out how to enable/use the auto-translate feature (English to Spanish). The description of the app also talks about auto-switching languages when typing. Thanks in advance for your suggestions.