pwd: 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 CentOS possible default full paths are:

/bin/pwd - from package: coreutils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/bin/pwd - from package: coreutils

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

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