  We investigate a generalization of Hopf algebra $\mathfrak{sl}_{q}(2)$ by
weakening the invertibility of the generator $K$, i.e. exchanging its
invertibility $KK^{-1}=1$ to the regularity $K\overline{K}K=K$. This leads to a
weak Hopf algebra $w\mathfrak{sl}_{q}(2)$ and a $J$-weak Hopf algebra
$v\mathfrak{sl}_{q}(2)$ which are studied in detail. It is shown that the
monoids of group-like elements of $w\mathfrak{sl}_{q}(2)$ and
$v\mathfrak{sl}_{q}(2)$ are regular monoids, which supports the general
conjucture on the connection betweek weak Hopf algebras and regular monoids.
Moreover, from $w\mathfrak{sl}_{q}(2)$ a quasi-braided weak Hopf algebra
$\overline{U}_{q}^{w}$ is constructed and it is shown that the corresponding
quasi-$R$-matrix is regular $R^{w}\hat{R}^{w}R^{w}=R^{w}$.
