diff --git a/CrashCourse.md b/CrashCourse.md
index 944d9f7..918506e 100644
--- a/CrashCourse.md
+++ b/CrashCourse.md
@@ -1,6 +1,6 @@
 # PowerShell Scripting Crash Course
 
-There are a few different ways to get started.
+After having followed the [README.md](./README.md), `.ps1` scripts in the same folder as `$PROFILE.CurrentUserAllHosts` will be available in `$env:PATH` globally:
 
 ```powershell
 # Open the $PROFILE folder
@@ -11,14 +11,85 @@ notepad "$(Split-Path -Parent $PROFILE.CurrentUserAllHosts)\my-script.ps1"
 codium "$(Split-Path -Parent $PROFILE.CurrentUserAllHosts)\my-script.ps1"
 ```
 
+# variables
+
+[PowerShell is as case-insensitive as possible.](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_case-sensitivity?view=powershell-7.3) This means `$MyInvocation` works just the same as `$mYinoCAtiOn` among other things. Coming from a Unix background and preferring some consistency I like to pretend it is case-sensitive so in this repo I'll strive for that but it's worth keeping in mind. Especially since the Microsoft docs use case a lot in variable and cmdlet names.
+
+Variables use `$` to distinguish themselves and can be set with `=`
+
+```powershell
+$a_variable = "this one is a string"
+$interpolate_a_string = "like this: $a_variable"
+```
+
+## booleans
+
+There are a few constants to know: `$true`, `$false`, `$null`. Empty strings (`""`, `''`), `$null` and `0` evaluate as `$false`
+
+# if and while
+
+There are a handful of [comparison operators](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_comparison_operators?view=powershell-7.3) which can be used with `if` or `while` like this:
+
+```powershell
+if ($val -eq "y") {
+  Write-Host "value is a y"
+}
+else {
+  Write-Host "value is not a y"
+}
+
+while ($num -lt 50) {
+  $num = $num + 1
+}
+```
+
 # param
 
-# Read-Host
+At the beginning of scripts and functions `param` list can be specified like this
+
+```powershell
+param(
+  [string]$name = "Anonymous",
+  [int]$age,
+  [switch]$silent
+)
+```
+
+There are [a lot of different powers](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3) behind the square bracket syntax, [including custom validation](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_functions_advanced_parameters?view=powershell-7.3#validatescript-validation-attribute), but these are the basics. Parameters are not mandatory by default use `[Parameter(Mandatory)]` for that. The above param block could be used in a script like this:
+
+```powershell
+if ($silent) { exit }
+Write-Host "Hello $name"
+if ($age) {
+  Write-Host "according to the -age you provided you are: $age"
+}
+```
+
+And run like this:
+
+```powershell
+name_and_age.ps1 -name "Rose" -age "27"
+```
+
+# functions
+
+Functions use `param` too (instead of parenthesis like other languages). The last value is the `return` result, (which you can also use to `return` early... or just regularly if you want)
+
+```powershell
+function My-Add {
+  param(
+    [Parameter(Mandatory)][int]$x,
+    [Parameter(Mandatory)][int]$y,
+  )
+
+  $x + $y
+}
+```
+
+# For and ForEach
 
 # Paths and Items
 
-# If, For and While
-
 # See Also
 
 - [About scripts (learn.microsoft.com)](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_scripts?view=powershell-7.3)
diff --git a/README.md b/README.md
index 709ac34..4a20139 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,7 @@ $env:PATH += ";$(Split-Path -Parent $MyInvocation.MyCommand.Path)"
 
 ## update_and_clean.ps1
 
-With this I've also added a [`update_and_clean.ps1`](./update_and_clean.ps1) script (in the `$PROFILE` folder) that will update Windows as well as `scoop` if it's installed and then run `bleachbit --preset --clean` (also only if installed) **which depends on whatever you've last checked in the BleachBit UI... so run that and set it up first!** The script will also try to re-inkoke itself as Administrator if you're not in an elevated session already... which is usually. If you're familiar with Arch Linux you might say `yay`!
+With this I've also added a [`update_and_clean.ps1`](./update_and_clean.ps1) script (in the `$PROFILE` folder) that will update Windows as well as `scoop` if it's installed and then run `bleachbit --preset --clean` (also only if installed) **which depends on whatever you've last checked in the BleachBit UI... so run that and set it up first!** The script will also try to re-invoke itself as Administrator if you're not in an elevated session already... which is usually. If you're familiar with Arch Linux you might say `yay`!
 
 Checkout the [Crash Course](./CrashCourse.md) for a terse guide on writing your own PowerShell scripts.
 
diff --git a/update_and_clean.ps1 b/update_and_clean.ps1
index 059bcc6..f1b25ab 100644
--- a/update_and_clean.ps1
+++ b/update_and_clean.ps1
@@ -8,7 +8,7 @@ If (!(New-Object Security.Principal.WindowsPrincipal $(
 ) {
   # and elevating hasn't already been tried
   if (!$elevated) {
-    # attmempt to become Administrator by re-invoking this script
+    # attempt to become Administrator by re-invoking this script
     Start-Process PowerShell -Verb RunAs -ArgumentList (
       '-noprofile -noexit -file "{0}" -elevated' -f ($MyInvocation.MyCommand.Definition)
     )