  We discuss excitations in nonrelativistic field theories with spontaneous
breaking of a continuous global symmetry. It is known that in such systems
there are two types of Goldstone bosons (Type A and Type B) whose dispersion
law is generically linear or quadratic, respectively. We show that Type B
Goldstone bosons may have gapped partners which we call almost-Goldstone
bosons. With some nondegeneracy assumption about the low-energy effective
action, the total number of Goldstone and almost-Goldstone bosons adds up to
the number of broken symmetry generators. We propose that deviations of the
dispersion law of Goldstone bosons from linearity at small momenta may serve as
a signature of small breaking of time-reversal symmetry.
