The latter case is peculiar in that the inquiry does not become transparent to itself until all these constitutive factors of the question have themselves become transparent.
The question about the meaning of Being is to be formulated. We must therefore discuss it with an eye to these structural items.
Inquiry, as a kind of seeking, must be guided beforehand by what is sought. So the meaning of Being must already be available to us in some way. As we have intimated, we always conduct our activities in an understanding of Being. Out of this understanding arise both the explicit question of the meaning of Being and the tendency that leads us towards its conception. We do not know what 'Being' means. But even if we ask, 'What is "Being"?', we keep within an understanding of the 'is', though we are unable to fix conceptually what that 'is' signifies. We do not even know the horizon in terms of which that meaning is to be grasped and fixed. But this vague average understanding of Being is still a Fact.
However much this understanding of Being (an understanding which is already available to us) may fluctuate and grow dim, and border on mere acquaintance with a word, its very indefiniteness is itself a positive phenomenon which needs to be clarified. An investigation of the meaning of  Being cannot be expected to give this clarification at the outset. If we are to obtain the clue we need for Interpreting this average understanding of Being, we must first develop the concept of Being. In the light of this concept and the ways in which it may be explicitly understood, we can make out what this obscured or still unilluminated understanding of Being means, and what kinds of obscuration—or hindrance to an explicit illumination—of the meaning of Being are possible and even inevitable.
Further, this vague average understanding of Being may be so infiltrated with traditional theories and opinions about Being that these remain hidden as sources of the way in which it is prevalently understood. What we seek when we inquire into Being is not something entirely unfamiliar, even if proximally1 we cannot grasp it at all.
In the question which we are to work out, what is asked about is Being—that which determines entities as entities, that on the basis of which [woraufhin] entities are already understood, however we may discuss them in detail.
1 'zunächst'. This word is of very frequent occurrence in Heidegger, and he will discuss his use of it on H. 370 below. In ordinary German usage the word may mean 'at first', 'to begin with', or 'in the first instance', and we shall often translate it in such ways. The word. is, however, cognate with the adjective 'nah' and its superlative 'nächst', which we shall usually translate as 'close' and 'closest' respectively; and Heidegger often uses 'zunächst' in the sense of 'most closely', when he is describing the most 'natural' and 'obvious' experiences which we have at an uncritical and pre-philosophical level. We have ventured to translate this Heideggerian sense of 'zunächst' as 'proximally', but there are many border-line cases where it is not clear whether Heidegger has in mind this special sense or one of the more general usages, and in such cases we have chosen whatever expression seems stylistically preferable.