Modes with azimuthal or poloidal wavenumber m = 1 can appear in the form of internal kinks that are described by the ideal magnetohydrodynamic approximation, or in the form of ’’reconnecting’’ modes that lead to the formation of magnetic islands. An analysis of these modes is developed for collisionless regimes, where the collisional electrical resistivity is negligible and the effects of finite ion inertia and mode-particle resonance play the most important role.