Why does だけ come before は?

Question

In a song I was listening to, there was the sentence:

僕はＥ缶だけは最後までとっておく

With the given translation:

I will only take the E-Tank at the very last moment.

I don't understand why だけ comes before は, since は seems to apply to Ｅ缶. It seems strange to me, I would expect: Ｅ缶は, i.e. I'm going to say something about Ｅ缶. Which is the case in the song. But with Ｅ缶だけは it seems like something is said about "only E-can". i.e. "I will take only the E-can at the end", instead of "I will take the E-can only at the end". Where the thing that "only" applies to changes.

Why does だけ come between は and the noun? Is this perhaps something that is done to make the song sound better?

Answer 1

僕はＥ缶だけは最後までとっておく

means:

I'll spare at least E-Tanks until the last moment.
I will use anything but E-Tanks before the last moment.

This だけ refers to E-Tanks, not "at the last moment" part. とっておく means "to spare / keep", not "to take / bring".

To be clear, he's not saying he's going to throw away items other than E-Tanks. Obviously it doesn't make sense :)

だけは and だけ are different:

• これだけ読みなさい。 Read only this. (Don't read others.)
• これだけは読みなさい。 Read at least this.
• このゲームだけ欲しい。 I only want this game. (I'm not interested in other games)
• このゲームだけは欲しい。 At least I want this game. (although I also want others)

Answer 2

The particle は serves to indicate that what follows it is true only of what precedes it. By using は, the speaker is saying, in effect, "This is what I'm going to say something about, OK? Now here's what I'm going to say." It's a way of focusing the hearer's attention on something before delivering some information about it, or asking a question about it. It therefore excludes other possibilities. And だけ serves to exclude possibilities other than what precedes it. E 缶だけ means "only the E-can". とっておく means "put aside [for future use]", "keep", "hang on to". E-缶だけ最後までとっておく would mean "I'll hold on to the E-can alone right to the end". By inserting は the speaker is reinforcing the fact, already established by だけ , that anything other than the E-can is excluded from what he/she is saying: "What I'm going to say applies only to the E-can and nothing else at all, got that? Right - here it is: I'm going to hang on to it to the very end." I'd suggest something like "Just the E-can, now - that I'm going to hold on to right to the end (never mind about the rest of the stuff)."