After being spared one grammar point this week, there is still lots of lovely new stuff to learn.

と限らない

This little function is quite useful and expresses the limit of something. The kanji 限 literally means limit, there と限らない means something like 'that is not limited to'. In more natural English we would translate this as 'it doesn't mean that. When used as an adverb 限り expresses, 'as far as', 'as long as' etc etc... For example,

僕が知る限りでは、ジョンさんはまだ大学で日本語を勉強している。
As long as I know, John is still studying Japanese at University.

ＦａｃｅｂｏｏｋとかＳｋｙｐｅを持っている限り日本に住んでいる友達を連絡できる。
I am able to contact my friends in Japan, so long as I have facebook and Skype.

When we use the function と限らない we can express the notion of something not being the way it is, let's have a look;

僕は日本語が上手だとは限らない
It doesn't mean I'm good at Japanese.

~からと言って

This can often follow the above, to devastating effect. It literally means 'just because'. For example,

僕は日本人からと言って、日本語が上手だとは限らない。
Just because I'm Japanese, doesn't mean I'm good at Japanese language.

You can often supplement this with 必ずしも to mean 'not necessarily mean'

日本語ができるし、背が高いからと言って、必ずしも日本に行った時に、日本の彼女ができるとは限らないでしょうね。
Just because you can speak Japanese and are tall, doesn't necessarily mean when you go to Japan, you will get a Japanese girlfriend.

~ずにはいられない

To understand this grammar point, you have to break it down. The first bit '~ずには' comes from the negative form of a verb meaning 'without doing something' (i.e. 食べずには - without eating.) And the second part comes from the neagtive potential form of いる (meaning unable to exist.)

Therefore something like 食べずにはいられない- I am unable to exist without eating (lol!)

A more natural translation would be;

去年日本に行った時に、名物を食べるより、イギリスの料理を食べずにはいられなかった。
When I went to Japan last year, Rather than eating the local specialities, I couldn't help eating British food.

You can form this with になる to express the changing state of something of you becoming to the point of doing this action. For example;

いつBar Oneに行っても、お酒を飲まずにいられなくなってしまう。
Whenever I go to Bar One, I can't help drinking alcohol.

~しかない

This expresses something like 'no option of doing' or 'no alternative to doing.'

先週試験を落ちたから、今から、毎日勉強するしかないでしょう。
Because I failed my exam last week, I have no option but to study everday from now on.