From your query, you seem to be looking to see if any line exists in the “MBAMSERVICE.LOG” file that does NOT contain the word “english”.
Is that what you are looking for?
If on the other hand, you want to know if there exists any line in the file that DOES contain “english”, then something like the following should work for you …
exists file "C:\Testing\servergroup.txt" whose (exists lines whose (it contains "english") of it)
Keep in mind that if your MBAMSERVICE.LOG file is “in use” by Malwarebytes, you may not be able to access it via Relevance until Malware Bytes releases it.