Open Sans is a typography with clean lines and neutral forms that was created especially for Google Fonts so the designer made an effort to offer a typography that adapts and reads well on all devices as well as on paper. And, it gets along well with many other fonts: it combines well with a typography as peculiar as Ambroise or as friendly as Proxima Nova.
BEST USED FOR
Body of text, menu, titles
COMBINES WELL WITH
+ EXAMPLE: Open Sans and Playfair Display