vouch for

基本解釋

It is that learning that a certification should vouch for.
因此，這個(gè)學(xué)習(xí)的過程才是認(rèn)證所要保證的。
Actually Lucille is right about the eating slowly but I can't vouch for the lying of one's age.
實(shí)際上露茜麗關(guān)于要慢慢地吃的觀點(diǎn)是對(duì)的，不過我不敢擔(dān)保謊報(bào)年齡也是。
While I can’t vouch for the fountain of health and youth claim, I have experienced the extra vitality that comes from eating these nutrient-dense foods.
雖然我不能保證優(yōu)等食品是健康和保持這一宣稱，但從我個(gè)人經(jīng)驗(yàn)了所得，我自身更多的活力，就是來自食用這些營養(yǎng)密集的食物。

These are people you know and you feel that you can vouch for their good intentions.
NPR: 5 min 45 sec
I've been traveling like a madman lately and can vouch for full planes and busy airports.
FORBES: Twenty Reasons to Be Optimistic
Is there really no one from Cranbrook that Romney can persuade to vouch for him?
FORBES: Bullying and Mitt Romney's Empathy Problem

If you say that you can or will vouch for someone, you mean that you can guarantee their good behaviour.
If you say that you can vouch for something, you mean that you have evidence from your own personal experience that it is true or correct.