When you have this error, it means that your system has by default, a line in /etc/fstab which indicates that if there is an error in the file system, that it should go into read-only mode, to prevent further corruption or dataloss.
You could use lsblk
to determine the partition name.
Use the command
sudo fsck -f /dev/sdxx
where “sdxx” is the partition of the hard drive that Linux resides on