I cannot believe the thought never occurred to him before.

These occur a few days before, during, or right after their period.

He saw something now that had not occurred to him before.

It was an idea that had never occurred to them before.

That hadn't occurred to him before, which made it no less true.

The same thing had occurred the evening before, at the hotel.

He wondered why it had not occurred to him before.

He wondered that the idea had not occurred to him before.

So simple, she wondered why the idea hadn't occurred to her before.

Such conditions may have occurred before without having been observed.

Other changes occurred before the start of the season as well.

They looked to each other, as if the question hadn't occurred to them before this.

This change, of course, occurred in some areas before others.

It was not a thought that would have occurred to him before today.

About 5% to 10% of cases occur before age 50.

It is likely his death occurred not long before the last date.

The international travel experience occurs during the summer before third year.

He likely continued to hold the office until his death, which occurred before 26 August 1254.

The final issue date is still in question and may not occur before 2015.

These may occur hours or weeks before the actual heart attack.