maintain means to keep in an existing state, to uphold or preserve, or to continue consistently over time. Its usage is often accompanied by an object, whether a thing, a condition, or an idea.
1. She maintained her composure in the face of danger.
2. They maintained the traditions that had been passed down in their family for generations.
3. The university maintains its high standards through its commitment to excellence.
be careful not to confuse 'maintain' with 'sustain,' as they have very different meanings; the former is far more likely to be used in a context involving status or condition, while the latter is more often associated with the idea of supplying energy or resources over a period of time.