Fix grammar in MerkleBlock error messages

diff --git a/bitcoin/src/consensus/error.rs b/bitcoin/src/consensus/error.rs
index 86a9f7cd..00c86936 100644
--- a/bitcoin/src/consensus/error.rs
+++ b/bitcoin/src/consensus/error.rs
@@ -99,7 +99,7 @@ impl<E: fmt::Debug + std::error::Error + 'static> std::error::Error for DecodeEr
 #[derive(Debug)]
 #[non_exhaustive]
 pub enum Error {
-    /// And I/O error.
+    /// An I/O error.
     Io(io::Error),
     /// Error parsing encoded object.
     Parse(ParseError),
diff --git a/bitcoin/src/merkle_tree/block.rs b/bitcoin/src/merkle_tree/block.rs
index 580923c3..837044b7 100644
--- a/bitcoin/src/merkle_tree/block.rs
+++ b/bitcoin/src/merkle_tree/block.rs
@@ -489,8 +489,8 @@ impl fmt::Display for MerkleBlockError {
             NoTransactions => write!(f, "partial Merkle tree contains no transactions"),
             TooManyTransactions => write!(f, "too many transactions"),
             TooManyHashes => write!(f, "proof contains more hashes than transactions"),
-            NotEnoughBits => write!(f, "proof contains less bits than hashes"),
-            NotAllBitsConsumed => write!(f, "not all bit were consumed"),
+            NotEnoughBits => write!(f, "proof contains fewer bits than hashes"),
+            NotAllBitsConsumed => write!(f, "not all bits were consumed"),
             NotAllHashesConsumed => write!(f, "not all hashes were consumed"),
             BitsArrayOverflow => write!(f, "overflowed the bits array"),
             HashesArrayOverflow => write!(f, "overflowed the hashes array"),