diff --git a/9-regular-expressions/11-regexp-groups/01-test-mac/task.md b/9-regular-expressions/11-regexp-groups/01-test-mac/task.md
index 029a4803..a2e799cf 100644
--- a/9-regular-expressions/11-regexp-groups/01-test-mac/task.md
+++ b/9-regular-expressions/11-regexp-groups/01-test-mac/task.md
@@ -16,5 +16,5 @@ alert( regexp.test('0132546789AB') ); // false (no colons)
 
 alert( regexp.test('01:32:54:67:89') ); // false (5 numbers, must be 6)
 
-alert( regexp.test('01:32:54:67:89:ZZ') ) // false (ZZ ad the end)
+alert( regexp.test('01:32:54:67:89:ZZ') ) // false (ZZ at the end)
 ```
diff --git a/9-regular-expressions/11-regexp-groups/03-find-decimal-numbers/solution.md b/9-regular-expressions/11-regexp-groups/03-find-decimal-numbers/solution.md
index c4349f9a..813d619e 100644
--- a/9-regular-expressions/11-regexp-groups/03-find-decimal-numbers/solution.md
+++ b/9-regular-expressions/11-regexp-groups/03-find-decimal-numbers/solution.md
@@ -1,4 +1,4 @@
-A positive number with an optional decimal part is (per previous task): `pattern:\d+(\.\d+)?`.
+A positive number with an optional decimal part is: `pattern:\d+(\.\d+)?`.
 
 Let's add the optional `pattern:-` in the beginning:
 
diff --git a/9-regular-expressions/11-regexp-groups/04-parse-expression/solution.md b/9-regular-expressions/11-regexp-groups/04-parse-expression/solution.md
index 130c57be..ac67519b 100644
--- a/9-regular-expressions/11-regexp-groups/04-parse-expression/solution.md
+++ b/9-regular-expressions/11-regexp-groups/04-parse-expression/solution.md
@@ -1,4 +1,4 @@
-A regexp for a number is: `pattern:-?\d+(\.\d+)?`. We created it in previous tasks.
+A regexp for a number is: `pattern:-?\d+(\.\d+)?`. We created it in the previous task.
 
 An operator is `pattern:[-+*/]`. The hyphen `pattern:-` goes first in the square brackets, because in the middle it would mean a character range, while we just want a character `-`.
 
diff --git a/9-regular-expressions/11-regexp-groups/article.md b/9-regular-expressions/11-regexp-groups/article.md
index e559fd87..e0ef00bd 100644
--- a/9-regular-expressions/11-regexp-groups/article.md
+++ b/9-regular-expressions/11-regexp-groups/article.md
@@ -249,7 +249,7 @@ The call to `matchAll` does not perform the search. Instead, it returns an itera
 
 So, there will be found as many results as needed, not more.
 
-E.g. there are potentially 100 matches in the text, but in a `for..of` loop we found 5 of them, then decided it's enough and make a `break`. Then the engine won't spend time finding other 95 matches.
+E.g. there are potentially 100 matches in the text, but in a `for..of` loop we found 5 of them, then decided it's enough and made a `break`. Then the engine won't spend time finding other 95 matches.
 ```
 
 ## Named groups