diff --git a/derive/src/enum.rs b/derive/src/enum.rs
index a4091966..f11f9ebe 100644
--- a/derive/src/enum.rs
+++ b/derive/src/enum.rs
@@ -114,7 +114,7 @@ pub fn generate(enum_args: &args::Enum) -> GeneratorResult<TokenStream> {
     if schema_enum_items.is_empty() {
         return Err(Error::new_spanned(
             &ident,
-            "An GraphQL Enum type must define one or more unique enum values.",
+            "A GraphQL Enum type must define one or more unique enum values.",
         )
         .into());
     }
diff --git a/derive/src/input_object.rs b/derive/src/input_object.rs
index 245b9f81..2cc216a3 100644
--- a/derive/src/input_object.rs
+++ b/derive/src/input_object.rs
@@ -154,7 +154,7 @@ pub fn generate(object_args: &args::InputObject) -> GeneratorResult<TokenStream>
     if get_fields.is_empty() {
         return Err(Error::new_spanned(
             &ident,
-            "An GraphQL Input Object type must define one or more input fields.",
+            "A GraphQL Input Object type must define one or more input fields.",
         )
         .into());
     }
diff --git a/derive/src/interface.rs b/derive/src/interface.rs
index 6cac3277..055e0aaa 100644
--- a/derive/src/interface.rs
+++ b/derive/src/interface.rs
@@ -124,7 +124,7 @@ pub fn generate(interface_args: &args::Interface) -> GeneratorResult<TokenStream
     if interface_args.fields.is_empty() {
         return Err(Error::new_spanned(
             &ident,
-            "An GraphQL Interface type must define one or more fields.",
+            "A GraphQL Interface type must define one or more fields.",
         )
         .into());
     }
diff --git a/derive/src/object.rs b/derive/src/object.rs
index c64aa1a8..c2dd195c 100644
--- a/derive/src/object.rs
+++ b/derive/src/object.rs
@@ -474,7 +474,7 @@ pub fn generate(
     if resolvers.is_empty() && create_entity_types.is_empty() {
         return Err(Error::new_spanned(
             &self_ty,
-            "An GraphQL Object type must define one or more fields.",
+            "A GraphQL Object type must define one or more fields.",
         )
         .into());
     }
diff --git a/derive/src/simple_object.rs b/derive/src/simple_object.rs
index 0eb017a1..5f7f4d35 100644
--- a/derive/src/simple_object.rs
+++ b/derive/src/simple_object.rs
@@ -132,7 +132,7 @@ pub fn generate(object_args: &args::SimpleObject) -> GeneratorResult<TokenStream
     if !object_args.dummy && resolvers.is_empty() {
         return Err(Error::new_spanned(
             &ident,
-            "An GraphQL Object type must define one or more fields.",
+            "A GraphQL Object type must define one or more fields.",
         )
         .into());
     }
diff --git a/derive/src/subscription.rs b/derive/src/subscription.rs
index 6ecace00..30d7898c 100644
--- a/derive/src/subscription.rs
+++ b/derive/src/subscription.rs
@@ -367,7 +367,7 @@ pub fn generate(
     if create_stream.is_empty() {
         return Err(Error::new_spanned(
             &self_ty,
-            "An GraphQL Object type must define one or more fields.",
+            "A GraphQL Object type must define one or more fields.",
         )
         .into());
     }
diff --git a/integrations/warp/src/subscription.rs b/integrations/warp/src/subscription.rs
index b895146e..60199e5e 100644
--- a/integrations/warp/src/subscription.rs
+++ b/integrations/warp/src/subscription.rs
@@ -19,7 +19,7 @@ use warp::{Filter, Rejection, Reply};
 /// #[Object]
 /// impl QueryRoot {
 ///     async fn value(&self) -> i32 {
-///         // An GraphQL Object type must define one or more fields.
+///         // A GraphQL Object type must define one or more fields.
 ///         100
 ///     }
 /// }
diff --git a/parser/src/types/service.rs b/parser/src/types/service.rs
index 49658177..185d2106 100644
--- a/parser/src/types/service.rs
+++ b/parser/src/types/service.rs
@@ -3,7 +3,7 @@
 use super::*;
 use async_graphql_value::Name;
 
-/// An GraphQL file or request string defining a GraphQL service.
+/// A GraphQL file or request string defining a GraphQL service.
 ///
 /// [Reference](https://spec.graphql.org/June2018/#Document).
 #[derive(Debug, Clone)]
diff --git a/src/schema.rs b/src/schema.rs
index d7e78ee5..f744b5ed 100644
--- a/src/schema.rs
+++ b/src/schema.rs
@@ -470,7 +470,7 @@ where
         .extensions(extensions)
     }
 
-    /// Execute an GraphQL query.
+    /// Execute a GraphQL query.
     pub async fn execute(&self, request: impl Into<Request>) -> Response {
         let request = request.into();
         match self.prepare_request(request).await {
@@ -482,7 +482,7 @@ where
         }
     }
 
-    /// Execute an GraphQL batch query.
+    /// Execute a GraphQL batch query.
     pub async fn execute_batch(&self, batch_request: BatchRequest) -> BatchResponse {
         match batch_request {
             BatchRequest::Single(request) => BatchResponse::Single(self.execute(request).await),
@@ -565,7 +565,7 @@ where
         }
     }
 
-    /// Execute an GraphQL subscription.
+    /// Execute a GraphQL subscription.
     pub fn execute_stream(
         &self,
         request: impl Into<Request>,
diff --git a/src/types/empty_mutation.rs b/src/types/empty_mutation.rs
index 86105549..daf4412e 100644
--- a/src/types/empty_mutation.rs
+++ b/src/types/empty_mutation.rs
@@ -21,7 +21,7 @@ use crate::{
 /// #[Object]
 /// impl QueryRoot {
 ///     async fn value(&self) -> i32 {
-///         // An GraphQL Object type must define one or more fields.
+///         // A GraphQL Object type must define one or more fields.
 ///         100
 ///     }
 /// }