معنی کلمه when

at the hour of; as; whereas

in what time; at the time of

at what time; at the hour which; as; at the time of; whereas

time, period of time

The baby is due in March,by when the new house should be finished.
by when : before or since which time.
بچه ماه مارس به دنیا می آد قبل از اون خونه جدید باید آماده شده باشه

He had climbed many a tree when he was a boy .

As always , he had been there when she needed him .

When it finally started down the runway , she closed her eyes .

Every child feels displaced to some degree when a new sibling arrives .