'Contemplate' Phrasal Verbs:
1. Mull over: to think about carefully; consider
E. g. A group of friends gathers to mull over what to do with a day off.
2. Brood over: to ponder morbidly or persistently
E. g. I know you're upset about failing your exam, but don't brood over it all weekend.
3. Meditate on: think deeply about (something)
E. g. He went off to meditate on the new idea.
4. Muse over: to consider something thoughtfully
E. g. We were just now musing over Sarah and the way she has changed.
5. Aspire to: direct one's hopes or ambitions towards achieving something.
E. g. We never thought that we might aspire to those heights.
6. Chew over: to think about or discuss something carefully for a long time
E. g. I've been chewing the problem over since last week.