Update example to use env. within expression

content/actions/learn-github-actions/variables.md

@@ -76,9 +76,11 @@ jobs:
 
 {% endraw %}
 
-You can access `env` variable values using runner environment variables or using contexts. The example above shows three custom variables being used as environment variables in an `echo` command: `$DAY_OF_WEEK`, `$Greeting`, and  `$First_Name`. The values for these variables are set, and scoped, at the workflow, job, and step level respectively. For more information on accessing variable values using contexts, see "[Using contexts to access variable values](#using-contexts-to-access-variable-values)."
+You can access `env` variable values using runner environment variables or using contexts. The example above shows three custom variables being used as runner environment variables in an `echo` command: `$DAY_OF_WEEK`, `$Greeting`, and `$First_Name`. The values for these variables are set, and scoped, at the workflow, job, and step level respectively. The interpolation of these variables happens on the runner.
 
-Because runner environment variable interpolation is done after a workflow job is sent to a runner machine, you must use the appropriate syntax for the shell that's used on the runner. In this example, the workflow specifies `ubuntu-latest`. By default, Linux runners use the bash shell, so you must use the syntax `$NAME`. If the workflow specified a Windows runner, you would use the syntax for PowerShell, `$env:NAME`. For more information about shells, see "[AUTOTITLE](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsshell)."
+The commands in the `run` steps of a workflow, or a referenced action, are processed by the shell you are using on the runner. The instructions in the other parts of a workflow are processed by {% data variables.product.prodname_actions %} and are not sent to the runner. You can use either runner environment variables or contexts in `run` steps, but in the parts of a workflow that are not sent to the runner you must use contexts to access variable values. For more information, see "[Using contexts to access variable values](#using-contexts-to-access-variable-values)."
+
+Because runner environment variable interpolation is done after a workflow job is sent to a runner machine, you must use the appropriate syntax for the shell that's used on the runner. In this example, the workflow specifies `ubuntu-latest`. By default, Linux runners use the bash shell, so you must use the syntax `$NAME`. By default, Windows runners use PowerShell, so you would use the syntax `$env:NAME`. For more information about shells, see "[AUTOTITLE](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsshell)."
 
 ### Naming conventions for environment variables
 
@@ -222,7 +224,9 @@ You can access environment variable values using the `env` context{% ifversion a
 
 In addition to runner environment variables, {% data variables.product.prodname_actions %} allows you to set and read `env` key values using contexts. Environment variables and contexts are intended for use at different points in the workflow.
 
-Runner environment variables are always interpolated on the runner machine. However, parts of a workflow are processed by {% data variables.product.prodname_actions %} and are not sent to the runner. You cannot use environment variables in these parts of a workflow file. Instead, you can use contexts. For example, an `if` conditional, which determines whether a job or step is sent to the runner, is always processed by {% data variables.product.prodname_actions %}. You can use a context in an `if` conditional statement to access the value of an variable.
+The `run` steps in a workflow, or in a referenced action, are processed by a runner. As a result, you can use runner environment variables here, using the appropriate syntax for the shell you are using on the runner - for example, `$NAME` for the bash shell on a Linux runner, or `$env:NAME` for PowerShell on a Windows runner. In most cases you can also use contexts, with the syntax {% raw %}`${{ CONTEXT.PROPERTY }}`{% endraw %}, to access the same value. The difference is that the context will be interpolated and replaced by a string before the job is sent to a runner. 
+
+However, you cannot use runner environment variables in parts of a workflow that are processed by {% data variables.product.prodname_actions %} and are not sent to the runner. Instead, you must use contexts. For example, an `if` conditional, which determines whether a job or step is sent to the runner, is always processed by {% data variables.product.prodname_actions %}. You must therefore use a context in an `if` conditional statement to access the value of an variable.
 
 {% raw %}
 
@@ -245,7 +249,15 @@ jobs:
 
 {% endraw %}
 
-In this modification of the earlier example, we've introduced an `if` conditional. The workflow step is now only run if `DAY_OF_WEEK` is set to "Monday". We access this value from the `if` conditional statement by using the [`env` context](/actions/learn-github-actions/contexts#env-context).
+In this modification of the earlier example, we've introduced an `if` conditional. The workflow step is now only run if `DAY_OF_WEEK` is set to "Monday". We access this value from the `if` conditional statement by using the [`env` context](/actions/learn-github-actions/contexts#env-context). The `env` context is not required for the variables referenced within the `run` command. They are referenced as runner environment variables and are interpolated after the job is received by the runner. We could, however, have chosen to interpolate those variables before sending the job to the runner, by using contexts. The resulting output would be the same. 
+
+{% raw %}
+
+```yaml
+run: echo "${{ env.Greeting }} ${{ env.First_Name }}. Today is ${{ env.DAY_OF_WEEK }}!"
+```
+
+{% endraw %}
 
 {% note %}
 
@@ -260,6 +272,8 @@ You will commonly use either the `env` or `github` context to access variable va
 | `env` | Reference custom variables defined in the workflow. | <span style="white-space: nowrap;">{% raw %}`${{ env.MY_VARIABLE }}`{% endraw %}</span> |
 | `github` | Reference information about the workflow run and the event that triggered the run. | <span style="white-space: nowrap;">{% raw %}`${{ github.repository }}`{% endraw %}</span> |
 
+{% data reusables.actions.context-injection-warning %}
+
 {% ifversion actions-configuration-variables %}
 
 ### Using the `vars` context to access configuration variable values