It changes enough text to English, to make it more navigable for now. Yes, the many dialog boxes and such will still be in German, but if OP wants to convert everything into English, they will need install media on floppies. Note that even the foreign language versions included the English files, they just weren't installed by default as back then every byte on HDD was precious.
If the files are present, the setting for changing that is in the system.ini [BOOT] section:
language.dll=langeng.dll
I would suggest getting a USB floppy drive to make bootable disks for that machine, given that it can only boot floppies or hard disk, and floppy is the only available removable media. As IDE was not standardized until 1994, the usual obvious suggestion of a CF to 44-pin IDE adapter won't work, as the drive electronics are probably on the motherboard.
At least with German you can type the words into Google Translate--I remember working on Windows NT 3.1 machines in Chinese and Japanese--I had to use a computer running the English version of NT next to them to see what the icons were and where in the dropdown menus to click! I remember drawing the yes/no/cancel characters once I figured out what they were...