  The idea of adding particles to construct amplitudes has been utilized in
various ways in exploring the structure of scattering amplitudes. This idea is
often called Inverse Soft Limit, namely it is the reverse mechanism of taking
particles to be soft. We apply the Inverse Soft Limit to the tree-level
amplitudes in $\mathcal{N}=4$ super Yang-Mills theory, which allows us to
generate full tree-level superamplitudes by adding "soft" particles in a
certain way. With the help from Britto-Cachazo-Feng-Witten recursion relations,
a systematic and concrete way of adding particles is determined recursively.
The amplitudes constructed solely by adding particles not only have manifest
Yangian symmetry, but also make the soft limit transparent. The method of
generating amplitudes by Inverse Soft Limit can also be generalized for
constructing form factors.
