diff --git a/args/args.go b/args/args.go
new file mode 100644
index 0000000..fe70f3a
--- /dev/null
+++ b/args/args.go
@@ -0,0 +1,14 @@
+package args
+
+import (
+	"fmt"
+	"strings"
+)
+
+func InterpolateCommand(rawCommand string, optionalPositionalArgs []string) string {
+	// replace $1, $2, etc. with the optional positional args
+	for i, arg := range optionalPositionalArgs {
+		rawCommand = strings.ReplaceAll(rawCommand, fmt.Sprintf("$%d", i+1), arg)
+	}
+	return rawCommand
+}
diff --git a/checks/command.go b/checks/command.go
index ebbbb90..6ba5ffe 100644
--- a/checks/command.go
+++ b/checks/command.go
@@ -3,16 +3,19 @@ package checks
 import (
 	"os/exec"
 
+	"github.com/bootdotdev/bootdev/args"
 	api "github.com/bootdotdev/bootdev/client"
 )
 
 func CLICommand(
 	assignment api.Assignment,
+	optionalPositionalArgs []string,
 ) []api.CLICommandResult {
 	data := assignment.Assignment.AssignmentDataCLICommand.CLICommandData
 	responses := make([]api.CLICommandResult, len(data.Commands))
 	for i, command := range data.Commands {
-		cmd := exec.Command("sh", "-c", command.Command)
+		finalCommand := args.InterpolateCommand(command.Command, optionalPositionalArgs)
+		cmd := exec.Command("sh", "-c", finalCommand)
 		b, err := cmd.Output()
 		if ee, ok := err.(*exec.ExitError); ok {
 			responses[i].ExitCode = ee.ExitCode()
diff --git a/cmd/run.go b/cmd/run.go
index 534a586..6909eae 100644
--- a/cmd/run.go
+++ b/cmd/run.go
@@ -12,7 +12,7 @@ func init() {
 // runCmd represents the run command
 var runCmd = &cobra.Command{
 	Use:    "run UUID",
-	Args:   cobra.ExactArgs(1),
+	Args:   cobra.MatchAll(cobra.RangeArgs(1, 10)),
 	Short:  "Run an assignment without submitting",
 	PreRun: compose(requireUpdated, requireAuth),
 	RunE:   submissionHandler,
diff --git a/cmd/submit.go b/cmd/submit.go
index 4621c97..bcb20f3 100644
--- a/cmd/submit.go
+++ b/cmd/submit.go
@@ -20,7 +20,7 @@ func init() {
 // submitCmd represents the submit command
 var submitCmd = &cobra.Command{
 	Use:    "submit UUID",
-	Args:   cobra.MatchAll(cobra.ExactArgs(1)),
+	Args:   cobra.MatchAll(cobra.RangeArgs(1, 10)),
 	Short:  "Submit an assignment",
 	PreRun: compose(requireUpdated, requireAuth),
 	RunE:   submissionHandler,
@@ -30,6 +30,11 @@ func submissionHandler(cmd *cobra.Command, args []string) error {
 	cmd.SilenceUsage = true
 	isSubmit := cmd.Name() == "submit"
 	assignmentUUID := args[0]
+	optionalPositionalArgs := []string{}
+	if len(args) > 1 {
+		optionalPositionalArgs = args[1:]
+	}
+
 	assignment, err := api.FetchAssignment(assignmentUUID)
 	if err != nil {
 		return err
@@ -46,16 +51,16 @@ func submissionHandler(cmd *cobra.Command, args []string) error {
 			fmt.Println("\nSubmitted! Check the lesson on Boot.dev for results")
 		}
 	case "type_cli_command":
-		results := checks.CLICommand(*assignment)
+		results := checks.CLICommand(*assignment, optionalPositionalArgs)
 		data := *assignment.Assignment.AssignmentDataCLICommand
 		if isSubmit {
 			failure, err := api.SubmitCLICommandAssignment(assignmentUUID, results)
 			if err != nil {
 				return err
 			}
-			render.CommandSubmission(data, results, failure)
+			render.CommandSubmission(data, results, failure, optionalPositionalArgs)
 		} else {
-			render.CommandRun(data, results)
+			render.CommandRun(data, results, optionalPositionalArgs)
 		}
 	default:
 		return errors.New("unsupported assignment type")
diff --git a/render/command.go b/render/command.go
index e85a9bc..e031c32 100644
--- a/render/command.go
+++ b/render/command.go
@@ -7,12 +7,12 @@ import (
 	"sync"
 	"time"
 
+	"github.com/bootdotdev/bootdev/args"
 	api "github.com/bootdotdev/bootdev/client"
 	"github.com/charmbracelet/bubbles/spinner"
+	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
 	"github.com/muesli/termenv"
-
-	tea "github.com/charmbracelet/bubbletea"
 )
 
 var green = lipgloss.NewStyle().Foreground(lipgloss.Color("2"))
@@ -131,7 +131,7 @@ func (m rootModel) View() string {
 		if !cmd.finished {
 			cmdStr += fmt.Sprintf("%s %s", s, cmd.command)
 		} else if !m.isSubmit {
-			cmdStr += fmt.Sprintf("%s", cmd.command)
+			cmdStr += cmd.command
 		} else if cmd.passed == nil {
 			cmdStr += gray.Render(fmt.Sprintf("?  %s", cmd.command))
 		} else if *cmd.passed {
@@ -215,16 +215,18 @@ func pointerToBool(a bool) *bool {
 func CommandRun(
 	data api.AssignmentDataCLICommand,
 	results []api.CLICommandResult,
+	optionalPositionalArgs []string,
 ) {
-	commandRenderer(data, results, nil, false)
+	commandRenderer(data, results, nil, false, optionalPositionalArgs)
 }
 
 func CommandSubmission(
 	data api.AssignmentDataCLICommand,
 	results []api.CLICommandResult,
 	failure *api.StructuredErrCLICommand,
+	optionalPositionalArgs []string,
 ) {
-	commandRenderer(data, results, failure, true)
+	commandRenderer(data, results, failure, true, optionalPositionalArgs)
 }
 
 func commandRenderer(
@@ -232,6 +234,7 @@ func commandRenderer(
 	results []api.CLICommandResult,
 	failure *api.StructuredErrCLICommand,
 	isSubmit bool,
+	optionalPositionalArgs []string,
 ) {
 	var wg sync.WaitGroup
 	ch := make(chan tea.Msg, 1)
@@ -259,7 +262,8 @@ func commandRenderer(
 		defer wg.Done()
 
 		for i, cmd := range data.CLICommandData.Commands {
-			ch <- startCmdMsg{cmd: cmd.Command}
+			finalCommand := args.InterpolateCommand(cmd.Command, optionalPositionalArgs)
+			ch <- startCmdMsg{cmd: finalCommand}
 			for _, test := range cmd.Tests {
 				ch <- startTestMsg{text: prettyPrint(test)}
 			}