Let's say Link does get the chance to say something. In your mind, what would he say?
I personally see Link saying things that an idealistic person or a genuine heroic figure would say. Something like what Simon in Gurren Lagann says or the classic "I am vengeance... " line spoken in Batman The Animated Series. Basically something to show how friendly he can be but how determined and badass he can be at the same time.
Whatever he says, I hope it isn't what you've mentioned, as it sounds a bit cheesy (and a bit dorky as well) to be honest.
lol jk jk
Anyway, Link does talk, and has had the ability to since
The Legend of Zelda's inception, or as far back as I can remember, which is quite a ways back. You [the player] simply chooses what you wish for him to say (in the dialog boxes). Many fans fail to realize this. It is far more pronounced in such games as
Ocarina of Time where Link's text can be seen as green and
Skyward Sword, in which multiple dialog options are given as to what you [the player] wishes for Link to say.
If you are referring to audible (voiced) dialog, I guess that'd be hard to imagine, seeing as how Link is...well...the link between you and the game world - a sort of avatar (for lack of a better term.) I guess it would all depend on his basic personality traits. By "basic", I mean the quirks that are sort of "built-into" Link's character at the beginning of a given game. These traits are usually very subtle, and as such, are subject to various personal interpretations on the part of the player. For example,
WW Link has been seen as a sort of sleepy-head with a bit of laziness. Some of his gestures when receiving the Hero's Garb at the start of his journey might also suggest a sort of reluctance to change clothes and/or a general distaste for the Hero of Time's (HoT) fashion sense (lol). Judging from this, I might interpret
WW Link's audible dialog as lazy and/or cool and laid-back. He'd probably say something along the lines of "Do I have to?" or "What a drag..." With character development, however, his dialog would likely morph into a more chivalrous tone (much like the HoT, I'd imagine.)
