Fix some possible typos and omissions in 1.5.5

1-js/05-data-types/05-array-methods/article.md

@@ -44,7 +44,7 @@ The syntax is:
 arr.splice(start[, deleteCount, elem1, ..., elemN])
 ```
 
-It modified `arr` starting from the index `start`: removes `deleteCount` elements and then inserts `elem1, ..., elemN` at their place. Returns the array of removed elements.
+It modifies `arr` starting from the index `start`: removes `deleteCount` elements and then inserts `elem1, ..., elemN` at their place. Returns the array of removed elements.
 
 This method is easy to grasp by examples.
 
@@ -700,7 +700,7 @@ alert(soldiers[1].age); // 23
 
 If in the example above we used `users.filter(army.canJoin)`, then `army.canJoin` would be called as a standalone function, with `this=undefined`, thus leading to an instant error.
 
-A call to `users.filter(army.canJoin, army)` can be replaced with `users.filter(user => army.canJoin(user))`, that does the same. The former is used more often, as it's a bit easier to understand for most people.
+A call to `users.filter(army.canJoin, army)` can be replaced with `users.filter(user => army.canJoin(user))`, that does the same. The latter is used more often, as it's a bit easier to understand for most people.
 
 ## Summary
 
@@ -711,7 +711,7 @@ A cheat sheet of array methods:
   - `pop()` -- extracts an item from the end,
   - `shift()` -- extracts an item from the beginning,
   - `unshift(...items)` -- adds items to the beginning.
-  - `splice(pos, deleteCount, ...items)` -- at index `pos` delete `deleteCount` elements and insert `items`.
+  - `splice(pos, deleteCount, ...items)` -- at index `pos` deletes `deleteCount` elements and inserts `items`.
   - `slice(start, end)` -- creates a new array, copies elements from index `start` till `end` (not inclusive) into it.
   - `concat(...items)` -- returns a new array: copies all members of the current one and adds `items` to it. If any of `items` is an array, then its elements are taken.
 
@@ -729,7 +729,7 @@ A cheat sheet of array methods:
   - `sort(func)` -- sorts the array in-place, then returns it.
   - `reverse()` -- reverses the array in-place, then returns it.
   - `split/join` -- convert a string to array and back.
-  - `reduce(func, initial)` -- calculate a single value over the array by calling `func` for each element and passing an intermediate result between the calls.
+  - `reduce/reduceRight(func, initial)` -- calculate a single value over the array by calling `func` for each element and passing an intermediate result between the calls.
 
 - Additionally:
   - `Array.isArray(arr)` checks `arr` for being an array.
@@ -738,7 +738,7 @@ Please note that methods `sort`, `reverse` and `splice` modify the array itself.
 
 These methods are the most used ones, they cover 99% of use cases. But there are few others:
 
-- [arr.some(fn)](mdn:js/Array/some)/[arr.every(fn)](mdn:js/Array/every) checks the array.
+- [arr.some(fn)](mdn:js/Array/some)/[arr.every(fn)](mdn:js/Array/every) check the array.
 
   The function `fn` is called on each element of the array similar to `map`. If any/all results are `true`, returns `true`, otherwise `false`.