The phrase "is key to understand" is a grammatically correct and usable phrase in written English.
You can use it when you want to emphasize the importance of understanding something. For example, "Developing good communication skills is key to understand one another."
Knowledge about the hydrological regime of wetlands is key to understand their physical and biological properties.
Identification of an appropriate threshold is key to understand the rainfall connectivity properties.
Identity construction is key to understand the refugee policies by the core states in Europe and in Asia.
Time-resolved structural information is key to understand the mechanism of biological processes, such as catalysis and signalling.
This selective invisibility is key to understand a city, as the design intervention may concentrate too much on what is there, overlooking the importance of what is hidden.
For open canopies, the partitioning of energy and water fluxes between the upper canopy and the under-storey is key to understand the competition mechanisms between layers.
The validation precisely focused on distinguishing which features are key to understand the size of discussion threads.
Mechanical properties of SS wires are key to understand the wire application clinically since it determines the force generated for tooth movement.
For us, it's key to understand not just what people are doing online, but the attitudes, motivations and beliefs which drive this".
Before we even can truly answer that question, though, it's key to understand the important role of cities in everyday life.
However, we still know little about cocoa pollination ecology and services, although they appear to be key to understand yield functions.
