Yes, every subspace can be expressed as the span of some vectors.
A subspace is defined as a subset of a vector space that satisfies certain properties. One of these properties is that a subspace must be closed under vector addition and scalar multiplication.
Given a subspace, we can always find a set of vectors such that the subspace is the span of those vectors. In other words, every subspace can be generated or "spanned" by a set of vectors.
For example, consider a two-dimensional subspace in three-dimensional space. This subspace can be spanned by two linearly independent vectors that lie within that subspace.
In general, if V is a subspace of a vector space, we can find a set of vectors {v1, v2, ..., vn} such that every vector in V can be expressed as a linear combination of those vectors (i.e., V is the span of {v1, v2, ..., vn}).
It's worth noting that the set of vectors that spans a subspace is not unique. There can be multiple sets of vectors that span the same subspace.