So it was natural for American doctors to study plants in their spare time.
You can study it in your spare time.
Despite the time allowed for study you may still need to study in your own time.
He worked in his father's business and could only study in his spare time.
Leaving school he continued to study in his free time whilst undertaking a series of jobs.
The family was too poor to send Joseph to secondary school, but he continued to study in his spare time.
They study dinosaurs up close, in their own time and environment.
Biology began to interest him more that year, and he studied natural history texts in his spare time.
From 1870 to 1875, Miller worked as a school administrator while studying law in his spare time.
During this period she studied music at the Metropolitan Opera in her free time.