ばかり is used to say “nothing but”. It is typically used in conversation rather than formal writing.
ばかり has a negative connotation when used in this way. For example, a guy walking into a bar with the hope of meetings girls and being confronted with a room full of men might say to his friend:
|Full of guys, eh.|
Now, he could say:
|Just guys, eh.|
But だけ is very neutral and so the former sentence is arguably more natural given the context.
|My son does nothing but play computer games.|
ばかり is used to suggest that out of many possible options only one has been chosen.
|My son is eats nothing but curry.|
Out of all the possible things he could eat, he eats only curry.
|My son eats nothing but food.|
Admittedly, this sounds strange in English as well, but just to drive the point home the sentence is unnatural in Japanese because you can only eat food—there is no other reasonable alternative.
If we want to say that he does nothing but eat we need to use ばかり with a different structure.
|【Verb: te Form】ばかり いる|
|My son does nothing but eat.|
|These two are always arguing.|
|Recently I’ve been spending almost all day in bed.|
Using the possessive particle after ばかり instead of the verb to exist we can modify a noun.
|【Verb: te Form】ばかりの【Noun】|
|Spend the summer holiday just playing around.|
|A student who is always skipping school.|
A bridging っ is often inserted in conversation.
|Nothing but lies.|