'Happen' in the Bible

Then I said to myself, “As it happens to the fool, so death will also happen to me. What use is it then for me to be extremely wise?” Then I said in my heart, “This too is vanity (meaningless).”

So I have seen that there is nothing better than that a man should be happy in his own works and activities, for that is his portion (share). For who will bring him [back] to see what will happen after he is gone?

For who [limited by human wisdom] knows what is good for man during his lifetime, during the few days of his futile life? He spends them like a shadow [staying busy, but achieving nothing of lasting value]. For who can tell a man what will happen after him [to his work, his treasure, his plans] under the sun [after his life is over]?

I again saw under the sun that the race is not to the swift and the battle is not to the strong, and neither is bread to the wise nor riches to those of intelligence and understanding nor favor to men of ability; but time and chance overtake them all.

Yet the fool multiplies words, though no man knows what will happen, and who can tell him what will come after he is gone?