ばかり actually is usually classified as a particle (the Koujien labels it a 助詞, for instance), and in fact "ばかりも" does appear on Google.

I believe that も can go after any particle except for は, and the sentence final particles.  However, がも and をも are both very limited in use in modern Japanese.

Last edited by yudantaiteki (2010 April 05, 5:27 pm)

What about it をも?  As I said, it's not used very often in modern Japanese, and certainly is not worth worrying about for someone that's asking basic questions.

Last edited by yudantaiteki (2010 April 05, 8:11 pm)

I don't know if I've ever seen をも, would appreciate some example sentences if you have any.

I've possibly been misreading をも where the text had を + a word starting with も. I thought I saw をも in Harry Potter 2 and Haruhi 1, but I can't find anything now.
I did find this sentence in an online story/novel,

浮かぶ疑問のどれをも口にすることのできないまま。

我々は、混迷の時代をくぐりぬけ、ついに新世紀の扉を開けたのです!!思えば、前世紀の二度にわたる世界大戦…そして、自らをも滅ぼす核の脅威。東西の冷戦。壁崩壊後の、相次ぐ地域紛争。そう、数々の脅威が我々を襲いました。
20th Century Boys, first chapter.


I remembered this one because I was utterly surprised when I first read it. "Wait a minute, they always told us you can't use も after は、が、を!" Sounds pretty formal from what I've read so far.