There is a lot of literature available on how people learn a second language. Understanding some of the complex ways in which learning progresses can enable one to teach in a more conscious and comprehensive way.
In my own mind I often conceptualise this metaphorically. You are probably familiar with the notion of ‘flat-pack’ furniture. There are some people who, on receipt of their flat-pack never glance at the instructions. There are some who follow each and every instruction meticulously (working from part to whole, rather than the other way around). There are those who do a mixture of the two: they may have an overall idea of how the piece of furniture is assembled, but like to confirm their ideas with the instructions. There are those who are happy to tackle part of the assembly using guesswork and common sense, but may refer to the instructions at some points where they feel less confident. There are those who need the instructions but actually prefer to be shown or to be given oral instructions.
I find this to be a useful metaphor for how different people learn a language because it accounts for different styles and approaches. There are those who are risk-takers, and those who are not; those who favour logical problem-solving and those who prefer an intuitive approach; those who are inductive and those who are deductive. There are also those learners who see the whole rather than the parts; there are also some learners who seem more open and receptive to learning, possibly because of previous learning experience, exposure or motivation or perhaps due to innate skills. Such metaphors may not be perfect analogy, but they can help us to interpret and understand differences in the classroom.