morse: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/morse - from package: morse-simulator
/usr/bin/morse - from package: morse

You may install the required package with command apt-get install {package}

Error in other languages:
morse: bevel nie gevind nie
morse: comandă negăsită
morse: comando não encontrado
morse: commande introuvable
morse: command not found
morse: käsku ei ole
morse: không tìm thấy lệnh
morse: komanda nerasta
morse: Kommando nicht gefunden.
morse: kommandot finns inte
morse: komut yok
morse: nie znaleziono polecenia
morse: níor aimsíodh an t-ordú
morse: no se encontró la orden
morse: no s'ha trobat l'ordre
morse: opdracht niet gevonden
morse: parancs nem található
morse: perintah tidak ditemukan
morse: príkaz nenájdený
morse: příkaz nenalezen
morse: команда не найдена
morse: командата не е открита
morse: 命令找不到
morse: コマンドが見つかりません