Bashエラー： "[yコマンドが見つかりません。"

このスクリプトを正しく実行しようとしています./passmark.sh line 7: [y command not found。

これは私のスクリプトです。

#!/bin/bash
# A simple script to ask a user for a pass mark and then display a grade
# the grade will be either an A, B, C, D or F
#
CONT=y
echo
while [$CONT = "y" ]
do
        echo -e "\"Please enter a pass mark: \c \""
        read MARK
        if [$MARK -ge "0" -a $MARK -lt "50"] ; then
                echo -e "\n \"F\" \n"
        elif [$MARK -ge "50" -a $MARK -lt "60"] ; then
                echo -e "\n \"D\" \n"
        elif [$MARK -ge "60" -a $MARK -lt "70"] ; then
                echo -e "\n \"C\" \n"
        elif [$MARK -ge "70" -a $MARK -lt "80"] ; then
                echo -e "\n \"B\" \n"
        elif [$MARK -ge "80" -a $MARK -lt "100"] ; then
                echo -e "\n \"A\" \n"
        else
                echo -e "\"Invalid input!!\n \""
        fi
        echo -e "\"Would you like to enter another pass mark? (y/n) \c \""
        read REPLY
        case "$REPLY" in
                n | N | no | No | NO ) CONT=n ;;
                *) ;;
        esac
echo
done