Student or Learner
Now that their children are grown up, Mr and Mrs Grayson live.. Themselves/by themselves?
From the sentence above, should we use word 'by' or not? And what's the reason?
What's the differenciation between them?
And what's different between using by and without using by?
Sometimes I heard people spoke without using by
I think the issue may be usages such as 'Don't tell me, I want to to guess it myself'/'Let me do it myself'... These could be expressed with no change in meaning if the 'myself' were 'by myself' or 'for myself'.
But in this case, the verb 'live' needs the preposition, because it's describing a way of living.
Also, sometimes, verb+by+myself/himself/herself/etc emphasizes that the person is doing it (the verb) alone without assistance. For example: I work by myself. = I work alone.
Sometimes, if the emphasis is that the person does it and doesn't need help (but being alone is not emphasized) then there might not be a by. For example: Oh don't worry, I can carry everything myself. It's not very heavy! (The speaker's carrying it all, but might not be physically alone.)
This is not a perfect rule, of course, but it might help you for now. If you're interested in this, I'd encourage you to listen and try to notice when 'by' is used, and not used, and try to find patterns yourself. That's often easier, more long-lasting, and less confusing than trying to find a quick answer from a grammar guide. Just a suggestion!