  Significant experimental progress has been made recently for observing
long-sought supersolid-like states in Bose-Einstein condensates, where spatial
translational symmetry is spontaneously broken by anisotropic interactions to
form a stripe order. Meanwhile, the superfluid stripe ground state was also
observed by applying a weak optical lattice that forces the symmetry breaking.
Despite of the similarity of the ground states, here we show that these two
symmetry breaking mechanisms can be distinguished by their collective
excitation spectra. In contrast to gapless Goldstone modes of the
\textit{spontaneous} stripe state, we propose that the excitation spectra of
the \textit{forced} stripe phase can provide direct experimental evidence for
the long-sought gapped pseudo-Goldstone modes. We characterize the
pseudo-Goldstone mode of such lattice-induced stripe phase through its
excitation spectrum and static structure factor. Our work may pave the way for
exploring spontaneous and forced/approximate symmetry breaking mechanisms in
different physical systems.
