What does ばかりで in "愉快な仲間ばかりで頼もしいぜ" mean

Question

愉快な仲間ばかりで頼もしいぜ

I can not understand the ばかりで in this sentence. Are ばかり and で stand together or both of them stand alone?

Answer 1

Note that there is no explicit 'all' in Japanese, though it is perhaps legitimately inferred from context:

...[and they] are only (or nothing but) cheerful companions, [so] I feel confident.

More simply, で is the -te form of the copula だ, compare

愉快な仲間ばかり[に囲まれて]頼もしいぜ。

where we have the -te form of 囲まれる.

Answer 2

ばかり is a particle, so ばかり and で stand alone in the sense that it is not a form of ばかりだ (there is no such na-adjective).

• 愉快な仲間ばかりだ All my companions are cheerful
• 頼もしい I feel confident/assured

だ is the standard auxiliary verb for assertion and is transformed into its 連用形=で. The construction is called 連用中止. See this question for example. So the sentence means the above two sentence combined with and.