Review comments

common-content/en/module/tools/awk/index.md

@@ -16,7 +16,7 @@ emoji= "💻"
 
 (Source, including text-only transcript: https://wizardzines.com/comics/awk/)
 
-Learn about it from its man page (and the backlog exercises).
+Learn about `awk` from its man page (and the backlog exercises).
 
 Some awk programs you should understand and be able to write:
 * `{print $2}`

common-content/en/module/tools/binary-and-hexidecimal-numbers/index.md

@@ -27,4 +27,4 @@ You can skip the Binary Logic section (but feel free to read it if you're curiou
 
 Do every exercise listed in the chapters.
 
-Make sure you have achieved the learning objectives listed on this page.
+Check you have achieved each learning objective listed on this page.

common-content/en/module/tools/cat-2/index.md

@@ -20,4 +20,4 @@ The man page contains a lot more information too. The man page lists everything
 
 Both can be useful.
 
-Make sure you have achieved the learning objectives, between reading the two sources.
+Check you have achieved each learning objective listed on this page.

common-content/en/module/tools/cpu-and-memory/index.md

@@ -25,4 +25,4 @@ Read chapter 7 of How Computers Really Work.
 
 Do every exercise listed in the chapters.
 
-Make sure you have achieved the learning objectives listed on this page.
+Check you have achieved each learning objective listed on this page.

common-content/en/module/tools/grep/index.md

@@ -21,7 +21,7 @@ For instance, the regular expression `^[0-9]*$` searches for a line which has on
 
 You can learn more about Regular Expressions at [RegexOne](https://regexone.com/). Many engineers just know the basic concepts, and Google for help when they need something more complicated, and this is fine.
 
-Learn about it from its man page (and the backlog exercises).
+Learn about `grep` from its man page (and the backlog exercises).
 
 Some commonly used flags you should understand:
 * `-c`

common-content/en/module/tools/individual-shell-tools/index.md

@@ -28,7 +28,7 @@ file1   file2
 ```
 
 Here we are saying: At a terminal prompt (signified by the `%`), run the command `ls`.\
-Below the command is some expected or example output (`file1    file2`) you will see when you run it.
+Below the command is the output (`file1    file2`) you should expect to see after you run the command. Sometimes this is the exact output you should expect. Sometimes _example_ outputs are given: these could vary according to your filesystem, username, or other variables.
 
 To call a program, we type its name and press enter.  Open a terminal and run:
 
@@ -60,6 +60,6 @@ Some programs take extra arguments. These may be optional or required. Extra arg
 
 Here we passed the optional argument `-r` and the optional argument `-B`. `-r` takes no value. We gave `-B` the value 1. 
 
-We could give flags in any order - `grep -B 1 -r "hello" .` works the same as `grep -r -B 1 "hello" .`.
+We call arguments that start with a `-` or `--` flags. We could give flags in any order - `grep -B 1 -r "hello" .` works the same as `grep -r -B 1 "hello" .`.
 
 `"hello"` and `.` are called positional arguments because they don't have a named flag before them. The program decides how to interpret them based on their position (order) in the command line, rather than a named flag coming before them. Their order matters.

common-content/en/module/tools/ls/index.md

@@ -10,7 +10,7 @@ emoji= "💻"
 
 `ls` is a tool for listing the files in a directory.
 
-Learn about it from its man page (and the backlog exercises).
+Learn about `ls` from its man page (and the backlog exercises).
 
 Some commonly used flags you should understand:
 * `-R`

common-content/en/module/tools/sed/index.md

@@ -18,9 +18,25 @@ emoji= "💻"
 
 `sed` executes a list of commands on a file. The most common commands are to replace some text with some other text, or to show or hide or delete lines that meet some criteria.
 
-Sed commands feature both a matcher (called an "address") specifying which lines to operate on, and an opeation (called a command) to perform on those lines.
+Sed commands feature both a matcher (called an "address") specifying which lines to operate on, and an operation (called a command) to perform on those lines.
 
-Learn about it from its man page (and the backlog exercises).
+{{<note type="Example">}}
+`sed '1,3 s/cat/dog/' some-file`
+
+Address: `1,3` - lines 1-3 of `some-file`\
+Command: `s/cat/dog/` - replace the first occurence of "cat" on each line with "dog"
+{{</note>}}
+
+If you don't specify an address, your command applies to the whole file:
+
+{{<note type="Example">}}
+`sed 's/cat/dog/' some-file`
+
+Address: Not specified, so every line of `some-file`\
+Command: `s/cat/dog/` - replace the first occurence of "cat" on each line with "dog"
+{{</note>}}
+
+Learn about `sed` from its man page (and the backlog exercises).
 
 Some sed commands you should understand and be able to write:
 * `s/cat/dog/`

common-content/en/module/tools/wc/index.md

@@ -11,7 +11,7 @@ emoji= "💻"
 
 `wc` is a tool for counting the bytes, words, or lines in a file.
 
-Learn about it from its man page (and the backlog exercises).
+Learn about `wc` from its man page (and the backlog exercises).
 
 Some commonly used flags you should understand:
 * `-c`