> what may 行ききる mean?

Well, I don't have an example with "ikikiru", at least now, so I'd like to use another one:
tabekiru - eat completely/perfectly

Wow, what many dishes we have today! [I'm wondering if I'll be able to eat everything perfectly...]
[zenbu tabekireru kana...]

"te shimau" has two meanings as you know, and when it's used one with "have eaten (in this case)", you can replace it and "-kiru" like above. But the impression is stronger to use "kiru" than using "te shimau" about this usage.

zenbu tabekireru kana...
= zenbu tabete shimaeru kana...

Shizu

Shizu-san,

"Perfectly" cannot be used this way in English. "Completely" is possible, but it is not very natural. Here's a more natural translation:

Wow! What a lot of dishes we have today! I wonder if I'll be able to finish (eating) it all...
("What a lot of dishes we have today!" could also be "We have so many dishes today!" or "We sure have a lot of dishes today!" The words "what many" will never be used together-- it is always "how many," but that is more appropriate for a question than for an exclamation.)

There's a television commercial in English for a medicine for an upset stomach. The actor in the commercial keeps repeating over and over again: "I can't believe I ate the whole thing!" Would any of the following be a natural translation?

Zenbu tabekitta no o shinjirarenai!
Zenbu tabekitte shinjirarenai!
Zenbu tabekitta no ga arienai!

Tony-san, ohayou gozaimasu.

Thank you for the correction and the explanation. Well, I, too, thought "what many" sounded strange, but I was not sure, hehe.

> Zenbu tabekitta no o shinjirarenai!
This should be as the natural expression:
Zenbu tabekitta no gashinjirarenai!

> Zenbu tabekitte shinjirarenai!
This should be:
Zenbu tabekitta nante shinjirarenai!

This sounds stronger than above about the speaker's emotion.

> Zenbu tabekitta no ga arienai!
This should be:
Zenbu tabekitta nante arienai!
or
Zenbu tabekitta nante koto wa arienai!

These expressions are natural as Japanese, but not so daily conversational. They sounds like ones in TV drama or novels which are more formal or written expression rather than conversational. Shortly, "shinjirarenai" is much common in our daily conversation more than "arienai (impossible).

Shizu

heys thanks for the replies =) btw is it that if we use "koto" it goes with "o" (x koto o shinjirarenai, but if we use "no" it goes with "ga" ? (x no ga shinjirarenai)

if so why is it that in the second case shinjiru uses ga instead of o?

"koto" and "no" are more or less interchangeable in this case, but "no" is more casual and used when speaking, whereas "koto" sounds more formal when spoken, and is used more in writing. Shizu-san presumably used "koto" with "arienai" exactly because she said that "arienai" is also an expression used more in writing.

Some verbs expressing a subjective relationship (like wakaru) use "ga" rather than "wo", but I was not aware that "shinjiru" was one of them. I have seen sentence examples where what is believed is followed either by "to" or by "wo"; so we will have to wait on Shizu-san's explanation of why "ga" is preferable in this case.

> is it that if we use "koto" it goes with "o" (x koto o shinjirarenai,
This is wrong: it should be "koto wa/ga shinjirarenai", or you can say "koto o shinjinai".

Shizu