USC researchers have found a trade-off between short-term and long-term memories that you can easily manipulate to your advantage. Although their research was in motor-memory, it would seem to apply to memory generally, regardless what you're trying to learn.

Need for the musical or physical routine to live in long-term memory? Accumulate repeated sessions of practice that are interrupted by school, sleep, eating, playing, TV, etc. It goes to long-term memory.

Work for 8 hours/day at a particular routine for a competition; you learn quickly and should do well in the competition. But a year from now, that routine will be hazy. Single-minded focus goes to quick learning via short-term memory.

Interruptions may be annoying but, apparently, they are essential to committing learning to long-term memory. Evolution seems to have inclined us to best remember things over the long term that we need to use regularly over the long term.

Their research concluded that focus on remembering something defaults to short-term memory. Spend hours studying for an exam, practicing a musical or athletic routine for hours–it all goes to short-term memory. So why do we always remember how to ride a bike? Because, you used your bike to go someplace to do something else and then return and do something else. The practice and memory was broken-up by other activity; and this non-exclusive, interrupted activity was repeated over a considerable period.

According to USC research, if you want to commit something to short-term memory, focus on it exclusively until you learn it. But if you want to commit something to long-term memory you'll have to break up the learning interspersed with other activities or with learning something different or differently.

So, if you want to converse in Hebrew, break up your learning sessions with your occupation, some vocabulary, your occupation, some listening and trying to understand spoken Hebrew, mowing the lawn, translating some Hebrew, washing the dishes, some more vocabulary, TV. You get the idea. You learn each area more slowly but the only way your brain can remember it over a number of sessions is to transfer it from short- to long-term memory.