diff --git a/compiler/rustc_error_codes/src/error_codes/E0591.md b/compiler/rustc_error_codes/src/error_codes/E0591.md
index f49805d9b4e..6ed8370e8c1 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0591.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0591.md
@@ -53,8 +53,8 @@ unsafe {
 ```
 
 Here, transmute is being used to convert the types of the fn arguments.
-This pattern is incorrect because, because the type of `foo` is a function
-**item** (`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
+This pattern is incorrect because the type of `foo` is a function **item**
+(`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
 is a function pointer, which is not zero-sized.
 This pattern should be rewritten. There are a few possible ways to do this:
 
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 441dc3c7e88..5a5e9db81a2 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -1283,7 +1283,7 @@ pub fn skip_region_resolution(&self) {
         assert!(old_value.is_none());
     }
 
-    /// Process the region constraints and return any any errors that
+    /// Process the region constraints and return any errors that
     /// result. After this, no more unification operations should be
     /// done -- or the compiler will panic -- but it is legal to use
     /// `resolve_vars_if_possible` as well as `fully_resolve`.
diff --git a/library/std/src/io/error/tests.rs b/library/std/src/io/error/tests.rs
index c897a5e8701..16c634e9afd 100644
--- a/library/std/src/io/error/tests.rs
+++ b/library/std/src/io/error/tests.rs
@@ -86,7 +86,7 @@ fn test_errorkind_packing() {
     assert_eq!(Error::from(ErrorKind::NotFound).kind(), ErrorKind::NotFound);
     assert_eq!(Error::from(ErrorKind::PermissionDenied).kind(), ErrorKind::PermissionDenied);
     assert_eq!(Error::from(ErrorKind::Uncategorized).kind(), ErrorKind::Uncategorized);
-    // Check that the innards look like like what we want.
+    // Check that the innards look like what we want.
     assert_matches!(
         Error::from(ErrorKind::OutOfMemory).repr.data(),
         ErrorData::Simple(ErrorKind::OutOfMemory),
diff --git a/library/std/src/sys/unix/kernel_copy.rs b/library/std/src/sys/unix/kernel_copy.rs
index 8f7abb55e23..94546ca09d0 100644
--- a/library/std/src/sys/unix/kernel_copy.rs
+++ b/library/std/src/sys/unix/kernel_copy.rs
@@ -20,7 +20,7 @@
 //! Since those syscalls have requirements that cannot be fully checked in advance and
 //! gathering additional information about file descriptors would require additional syscalls
 //! anyway it simply attempts to use them one after another (guided by inaccurate hints) to
-//! figure out which one works and and falls back to the generic read-write copy loop if none of them
+//! figure out which one works and falls back to the generic read-write copy loop if none of them
 //! does.
 //! Once a working syscall is found for a pair of file descriptors it will be called in a loop
 //! until the copy operation is completed.
diff --git a/src/test/ui/async-await/issue-64130-1-sync.rs b/src/test/ui/async-await/issue-64130-1-sync.rs
index af83f14bbda..1714cec5221 100644
--- a/src/test/ui/async-await/issue-64130-1-sync.rs
+++ b/src/test/ui/async-await/issue-64130-1-sync.rs
@@ -1,7 +1,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the specialized async-await-specific error when futures don't implement an
+// This tests the specialized async-await-specific error when futures don't implement an
 // auto trait (which is specifically Sync) due to some type that was captured.
 
 struct Foo;
diff --git a/src/test/ui/async-await/issue-64130-2-send.rs b/src/test/ui/async-await/issue-64130-2-send.rs
index 2362831d8b8..7a6e5952cb9 100644
--- a/src/test/ui/async-await/issue-64130-2-send.rs
+++ b/src/test/ui/async-await/issue-64130-2-send.rs
@@ -1,7 +1,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the specialized async-await-specific error when futures don't implement an
+// This tests the specialized async-await-specific error when futures don't implement an
 // auto trait (which is specifically Send) due to some type that was captured.
 
 struct Foo;
diff --git a/src/test/ui/async-await/issue-64130-3-other.rs b/src/test/ui/async-await/issue-64130-3-other.rs
index 52801c35ba3..630fb2c41cd 100644
--- a/src/test/ui/async-await/issue-64130-3-other.rs
+++ b/src/test/ui/async-await/issue-64130-3-other.rs
@@ -2,7 +2,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the unspecialized async-await-specific error when futures don't implement an
+// This tests the unspecialized async-await-specific error when futures don't implement an
 // auto trait (which is not Send or Sync) due to some type that was captured.
 
 auto trait Qux {}
diff --git a/src/test/ui/const-generics/occurs-check/unused-substs-2.rs b/src/test/ui/const-generics/occurs-check/unused-substs-2.rs
index 9a73f1a53e5..9b1212694f5 100644
--- a/src/test/ui/const-generics/occurs-check/unused-substs-2.rs
+++ b/src/test/ui/const-generics/occurs-check/unused-substs-2.rs
@@ -1,7 +1,7 @@
 #![feature(generic_const_exprs)]
 #![allow(incomplete_features)]
 
-// The goal is is to get an unevaluated const `ct` with a `Ty::Infer(TyVar(_#1t)` subst.
+// The goal is to get an unevaluated const `ct` with a `Ty::Infer(TyVar(_#1t)` subst.
 //
 // If we are then able to infer `ty::Infer(TyVar(_#1t) := Ty<ct>` we introduced an
 // artificial inference cycle.
diff --git a/src/test/ui/const-generics/occurs-check/unused-substs-3.rs b/src/test/ui/const-generics/occurs-check/unused-substs-3.rs
index 0d38bd39351..d5aeab47e62 100644
--- a/src/test/ui/const-generics/occurs-check/unused-substs-3.rs
+++ b/src/test/ui/const-generics/occurs-check/unused-substs-3.rs
@@ -1,7 +1,7 @@
 #![feature(generic_const_exprs)]
 #![allow(incomplete_features)]
 
-// The goal is is to get an unevaluated const `ct` with a `Ty::Infer(TyVar(_#1t)` subst.
+// The goal is to get an unevaluated const `ct` with a `Ty::Infer(TyVar(_#1t)` subst.
 //
 // If we are then able to infer `ty::Infer(TyVar(_#1t) := Ty<ct>` we introduced an
 // artificial inference cycle.
diff --git a/src/test/ui/deprecation/deprecation-lint.rs b/src/test/ui/deprecation/deprecation-lint.rs
index 65cc4e2ef1e..0417e952eb7 100644
--- a/src/test/ui/deprecation/deprecation-lint.rs
+++ b/src/test/ui/deprecation/deprecation-lint.rs
@@ -51,7 +51,7 @@ fn test() {
 
         let _ = nested::DeprecatedTupleStruct (1); //~ ERROR use of deprecated tuple struct `deprecation_lint::nested::DeprecatedTupleStruct`: text
 
-        // At the moment, the lint checker only checks stability in
+        // At the moment, the lint checker only checks stability
         // in the arguments of macros.
         // Eventually, we will want to lint the contents of the
         // macro in the module *defining* it. Also, stability levels
diff --git a/src/test/ui/explain.stdout b/src/test/ui/explain.stdout
index 62f1a7f98ea..ef1d866c3ff 100644
--- a/src/test/ui/explain.stdout
+++ b/src/test/ui/explain.stdout
@@ -47,8 +47,8 @@ unsafe {
 ```
 
 Here, transmute is being used to convert the types of the fn arguments.
-This pattern is incorrect because, because the type of `foo` is a function
-**item** (`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
+This pattern is incorrect because the type of `foo` is a function **item**
+(`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
 is a function pointer, which is not zero-sized.
 This pattern should be rewritten. There are a few possible ways to do this:
 
diff --git a/src/test/ui/issues/issue-29746.rs b/src/test/ui/issues/issue-29746.rs
index 428cc637f55..3470a7e09ad 100644
--- a/src/test/ui/issues/issue-29746.rs
+++ b/src/test/ui/issues/issue-29746.rs
@@ -7,7 +7,7 @@ macro_rules! zip {
         zip!([$($rest),*], $a.zip($b), (x,y), [x,y])
     };
 
-    // Intermediate steps to build the zipped expression, the match pattern, and
+    // Intermediate steps to build the zipped expression, the match pattern
     //  and the output tuple of the closure, using macro hygiene to repeatedly
     //  introduce new variables named 'x'.
     ([$a:expr, $($rest:expr),*], $zip:expr, $pat:pat, [$($flat:expr),*]) => {
diff --git a/src/test/ui/issues/issue-75907.rs b/src/test/ui/issues/issue-75907.rs
index 1534b6d07de..6da99cf6435 100644
--- a/src/test/ui/issues/issue-75907.rs
+++ b/src/test/ui/issues/issue-75907.rs
@@ -1,4 +1,4 @@
-// Test for for diagnostic improvement issue #75907
+// Test for diagnostic improvement issue #75907
 
 mod foo {
     pub(crate) struct Foo(u8);
diff --git a/src/test/ui/issues/issue-75907_b.rs b/src/test/ui/issues/issue-75907_b.rs
index e3074778233..fdfc5907c16 100644
--- a/src/test/ui/issues/issue-75907_b.rs
+++ b/src/test/ui/issues/issue-75907_b.rs
@@ -1,4 +1,4 @@
-// Test for for diagnostic improvement issue #75907, extern crate
+// Test for diagnostic improvement issue #75907, extern crate
 // aux-build:issue-75907.rs
 
 extern crate issue_75907 as a;
diff --git a/src/test/ui/lint/lint-stability-deprecated.rs b/src/test/ui/lint/lint-stability-deprecated.rs
index bdc66e83083..74c35083e60 100644
--- a/src/test/ui/lint/lint-stability-deprecated.rs
+++ b/src/test/ui/lint/lint-stability-deprecated.rs
@@ -130,7 +130,7 @@ fn test() {
         let _ = UnstableTupleStruct (1);
         let _ = StableTupleStruct (1);
 
-        // At the moment, the lint checker only checks stability in
+        // At the moment, the lint checker only checks stability
         // in the arguments of macros.
         // Eventually, we will want to lint the contents of the
         // macro in the module *defining* it. Also, stability levels
diff --git a/src/test/ui/proc-macro/meta-macro-hygiene.rs b/src/test/ui/proc-macro/meta-macro-hygiene.rs
index 62968ea54e0..70b8d8da19b 100644
--- a/src/test/ui/proc-macro/meta-macro-hygiene.rs
+++ b/src/test/ui/proc-macro/meta-macro-hygiene.rs
@@ -19,8 +19,8 @@ macro_rules! produce_it {
         // `print_def_site!` will respan the `$crate` identifier
         // with `Span::def_site()`. This should cause it to resolve
         // relative to `meta_macro`, *not* `make_macro` (despite
-        // the fact that that `print_def_site` is produced by
-        // a `macro_rules!` macro in `make_macro`).
+        // the fact that `print_def_site` is produced by a
+        // `macro_rules!` macro in `make_macro`).
         meta_macro::print_def_site!($crate::dummy!());
     }
 }
diff --git a/src/test/ui/proc-macro/meta-macro-hygiene.stdout b/src/test/ui/proc-macro/meta-macro-hygiene.stdout
index 2494af1208f..6b7b0c819cc 100644
--- a/src/test/ui/proc-macro/meta-macro-hygiene.stdout
+++ b/src/test/ui/proc-macro/meta-macro-hygiene.stdout
@@ -35,8 +35,8 @@ macro_rules! produce_it
         // `print_def_site!` will respan the `$crate` identifier
         // with `Span::def_site()`. This should cause it to resolve
         // relative to `meta_macro`, *not* `make_macro` (despite
-        // the fact that that `print_def_site` is produced by
-        // a `macro_rules!` macro in `make_macro`).
+        // the fact that `print_def_site` is produced by a
+        // `macro_rules!` macro in `make_macro`).
     }
 }