inetutils-talk: 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/inetutils-talk - from package: inetutils-talk

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

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