What is the sentence for friendship?

There isn't a single "sentence" for friendship, as it's a complex concept with many facets. You could say:

* Friendship is a precious gift. (This emphasizes its value)

* True friends are always there for you. (This highlights support and loyalty)

* Friendship makes life richer and more meaningful. (This focuses on its impact)

However, the best way to express the concept of friendship depends on the context and what you want to emphasize. You could also use a quote, a poem, or even a story to convey its meaning.