  We present simulations of the capabilities of the ngVLA to image at $\sim
0.75$ kpc resolution ($0.085"$), molecular line emission from star forming disk
galaxies at high redshift. The results are compared to the current capabilities
of ALMA. ALMA can detect the integrated emission, and determine the velocity
gradient and size across the brighter emission regions of the galaxy. The ngVLA
is a factor $\sim 6$ more sensitive at the adopted spatial and velocity
resolution. This sensitivity is needed to recover the detailed column density
distribution, velocity field, and velocity dispersion at full resolution. The
ngVLA will enable detailed analysis of spectral line profiles at $0.75$~kpc
resolution, even in relatively faint regions. The ngVLA will trace the rotation
curves to large radii, and recover sub-structure in the disks, such as clumps,
spiral arms, bars, and rings. Detection of these features is crucial in order
to assess how cold gas precipitates the formation of stars at high redshift.
