diff --git a/src/api/archive_unstable_body.md b/src/api/archive_unstable_body.md
index f1132dc..b88d6e1 100644
--- a/src/api/archive_unstable_body.md
+++ b/src/api/archive_unstable_body.md
@@ -2,7 +2,7 @@
 
 **Parameters**:
 
-- `hash`: String containing the hexadecimal-encoded hash of the header of the block whose body must be retrieved.
+- `hash`: String containing a hexadecimal-encoded hash of the header of the block whose body will be retrieved.
 
 **Return value**: If a block with that hash is found, an array of strings containing the hexadecimal-encoded SCALE-codec-encoded transactions in that block. If no block with that hash is found, `null`.
 
diff --git a/src/api/archive_unstable_hashByHeight.md b/src/api/archive_unstable_hashByHeight.md
index 6dda836..7ca0b36 100644
--- a/src/api/archive_unstable_hashByHeight.md
+++ b/src/api/archive_unstable_hashByHeight.md
@@ -4,7 +4,7 @@
 
 - `height`: Integer representing the height of the block.
 
-**Return value**: Array (possibly empty) of strings containing an hexadecimal-encoded hash of a block header.
+**Return value**: Array (possibly empty) of strings containing a hexadecimal-encoded hash of a block header.
 
 The JSON-RPC client must find the blocks (zero, one, or more) whose height is the one passed as parameter. If the `height` is inferior or equal to the finalized block height, then only finalized blocks must be fetched and returned.
 
diff --git a/src/api/archive_unstable_storage.md b/src/api/archive_unstable_storage.md
index 4fdeaec..248edb0 100644
--- a/src/api/archive_unstable_storage.md
+++ b/src/api/archive_unstable_storage.md
@@ -2,7 +2,7 @@
 
 **Parameters**:
 
-- `hash`: String containing an hexadecimal-encoded hash of the header of the block whose storage to fetch.
+- `hash`: String containing a hexadecimal-encoded hash of the header of the block whose storage to fetch.
 - `key`: String containing the hexadecimal-encoded key to fetch in the storage.
 - `childTrie`: `null` for main storage look-ups, or a string containing the hexadecimal-encoded key of the child trie of the "default" namespace.
 - `includeDescendants`: Boolean indicating whether the key-values of all the descendants of the `key` should be returned as well.
diff --git a/src/api/chainHead_unstable_body.md b/src/api/chainHead_unstable_body.md
index 7f9fc3e..f8b6c54 100644
--- a/src/api/chainHead_unstable_body.md
+++ b/src/api/chainHead_unstable_body.md
@@ -3,7 +3,7 @@
 **Parameters**:
 
 - `followSubscription`: An opaque string that was returned by `chainHead_unstable_follow`.
-- `hash`: String containing an hexadecimal-encoded hash of the header of the block whose body to fetch.
+- `hash`: String containing a hexadecimal-encoded hash of the header of the block whose body will be retrieved.
 
 **Return value**: A JSON object.
 
diff --git a/src/api/chainHead_unstable_storage.md b/src/api/chainHead_unstable_storage.md
index 695b600..695d198 100644
--- a/src/api/chainHead_unstable_storage.md
+++ b/src/api/chainHead_unstable_storage.md
@@ -3,7 +3,7 @@
 **Parameters**:
 
 - `followSubscription`: An opaque string that was returned by `chainHead_unstable_follow`.
-- `hash`: String containing an hexadecimal-encoded hash of the header of the block whose storage to fetch.
+- `hash`: String containing a hexadecimal-encoded hash of the header of the block whose storage to fetch.
 - `items`: Array of objects. The structure of these objects is found below.
 - `childTrie`: `null` for main storage look-ups, or a string containing the hexadecimal-encoded key of the child trie of the "default" namespace.