en_tn/jhn/16/20.md

Truly, truly, I say to you

Translate this the way your language emphasizes that what follows is important and true. See how you translated this in John 1:51.

but the world will be glad

Here the "world" is a metonym for the people who oppose God. Alternate translation: "but the people who oppose God will be glad" (See: rc://en/ta/man/translate/figs-metonymy)

but your sorrow will be turned into joy

You can translate this in an active form. Alternate translation: "but your sadness will become joy" or "but afterwards instead of being sad you will be very happy" (See: rc://en/ta/man/translate/figs-activepassive)