The thought process is one of the great mysteries of the world; it is as fascinating as it is complicated. Nothing has intrigued man more than the instinctive or conscious way in which one reacts in various situations.
Thus, thinking seems to have two courses of action: a fast one and a slow one. Fast thinking is unconscious, it happens effortlessly and instinctively, like when we instantly read the expression on the face of a person. Conversely, slow thinking is conscious, it implies a lot of effort and is helpful when the solution to a problem or situation requires a more in-depth analysis.
Both types of thinking are required in order to translate words/structures from one language into another. The first phase of the process is the decoding. This occurs instantly by associating words or by resorting to predefined mental connections. The second phase of translation is understanding the decoded word, a process which appeals to slow, in-depth, analytical thinking. This phase takes more time and cannot be carried out by instinctive associations, it must be thought out consciously. The third phase is the recoding, meaning choosing the equivalent term in the target language. This may be more or less difficult, depending on whether the language in which the translation is performed is the mother tongue or a learned language.
Thus, we see that the human mind goes through successive phases in order to come up, finally, with an accepted linguistic equivalent. One cannot ignore the intellectual effort required for this process, which everybody knows that it is more exhausting than physical effort.