Plz helpp

[harsh mist]

What is the problem?

Do u not understand the question

Or can’t u come up with examples

[dawn geode]

I’m not sure but think of the vectorial space of polynomials K[X] and the subspaces Ki[X] that is the set of polynomials with a degree inferior or equal to i, this can be an example

[grave dock]

take the 2 common 1st examples of infinite dimensional vector spaces, polynomial space $\mathbb{K}[x]$ and the space of sequences $L:={(x_1,x_2,...)|x_i\in\mathbb{K}}$. Both have 'canonical' finite dimensional subspaces.
$\mathbb{K}_{\leq n}[x]$ being the space of polynomials of at most degree $n$, and $L_n$ being the subspace of sequences with finite support, ie after $n$ terms the sequences are constantly $0$.