  In this paper we explore some basic properties of quasi-Banach function
spaces which are important in applications. Namely, we show that they posses a
generalised version of Riesz--Fischer property, that embeddings between them
are always continuous and that the dilation operator is bounded on them. We
also provide a characterisation of separability for quasi-Banach function
spaces over the Euclidean space. Furthermore, we extend the classical
Riesz--Fischer theorem to the context of quasinormed spaces and, as a
consequence, obtain an alternative proof of completeness of quasi-Banach
function spaces.
