turnin: 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/turnin - from package: turnin-ng

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

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