If there’s going to be any agreement, it’s necessary for one of us to make a concession. The only way to reach a compromise is to make a concession. The negotiation was finally successful when the other party backed down and compromised on a key issue. From these examples, we notice a couple things: First, we usually say to make a concession and to reach a compromise. A compromise is a kind of agreement, and a concession is something we do to reach it. Note, however, that in the last example compromise is used as a verb. In this case, to.
