skk: 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/skk - from package: libskk-dev

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

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