Sentence examples for know this for certain from inspiring English sources

An upturn in crime in a very few cities is probably a local bump on a bigger, encouraging graph, but no one can know this for certain.

Also, I don't know this for certain, but I wouldn't be at all surprised if Jérôme Valcke [Fifa's secretary general, who faces strong evidence that he knew of the alleged bribe] did say to Blatter, 'I'm not taking the rap for this, you agreed.' That's one.

(But, again, we don't know this for certain).

They may happen to be true, but we cannot know this for certain in any particular case.

In fact, it's possible that we can still see the silent echoes of this dual domestication today: some modern dogs may carry traces of DNA from that ancient European domestication, but this is difficult to know this for certain since no one has yet managed to recover any DNA from those ancient dogs.

We know this for certain.

He knew this for certain, he said, because he had talked to the local people.

She knew this for certain because next to the for-sale sign in the photo there was a bumper sticker that read "I ♥ Gstaad".

A search of the scientific literature revealed that although most scientists assumed that pufferfish hold their breath whilst inflated, no one knew this for certain.

She knew this for certain because next to the for-sale sign in the photo there was a bumper sticker that read "I Gstaad".

The windows, blocks and bowls are thought to have formed an elaborate clock, powered by running water, that sounded the hours of prayer — though no one knows this for certain.