i Register
In some senses, ponder is marked as obsolete, colloquial. Watch for register when choosing this word.
ADV
carefully, deeply, hard
(for) a moment
He pondered for a moment, then decided to accept the job offer.
VERB + PONDER
leave sb to
She left him to ponder the difficult decision for a few days before asking for his answer.
be forced to
PREP
about
She sat quietly, pondering about whether to accept the job offer in another city.
on
She sat quietly in the café, pondering on whether to accept the job offer.
over
She sat quietly, pondering over whether to accept the job offer in another city.