Fix typo in RBF FAQ post

Author: sevastos

_posts/en/pages/faq/2016-01-21-rbf-faq.md

@@ -89,7 +89,7 @@ Bitcoin Core 0.12 will be released around February 2016 and will include opt-in
 
 ## Is opt-in RBF only useful for adjusting fees?
 
-No, another useful thing wallets can do with opt-in RBF is combine two or payments into a single payment when the first payment hasn't confirmed yet. This can save a large number of bytes and transaction fees even though the replacement will have pay a higher fee than the original.
+No, another useful thing wallets can do with opt-in RBF is combine two or more payments into a single payment when the first payment hasn't confirmed yet. This can save a large number of bytes and transaction fees even though the replacement will have to pay a higher fee than the original.
 
 Opt-in RBF can also be used to implement more advanced cooperative stability schemes such as [transaction cut-through](https://bitcointalk.org/index.php?topic=281848.0).