A surface quasielastic light scattering (SQELS) and electrocapillary wave (ECW) study of a monolayer of 1-dodecanol, obtained by placing a reservoir drop of the alcohol on top of a water surface, has been carried out as a function of temperature at different wavevectors. This monolayer goes through a liquid-solid phase transition at 312.1 K, more than 14 K above the freezing of bulk 1-dodecanol. The fit of the SQELS spectra gives the frequency, omega(c), and the temporal damping, Delta omega(c), of thermally induced capillary waves. In all the temperature range omega(c) follows Kelvin-like behavior (i.e., omega(c) similar to q(3/2)) leading to values of the apparent dynamic surface tension lower than the static ones. In addition the damping follows, Delta omega(c) similar to q(1.2-1.4) very far from the expected similar to q(2) dispersion behavior. Both wave parameters show temperature trends compatible with the expected liquid-solid 2D phase transition at around 312 K. The expansion of the frequency range by using the ECW technique, shows that our experimental results cover the regions q less than or equal to q(R) less than or equal to q, where qR is the wavevector at which capillary-dilational resonance takes place. Within the classical elastohydrodynamic theory, our results can be accounted for if the dilational viscosity, kappa, takes a negative sign. In these conditions mode mixing takes place for q greater than or equal to q(R). Alternatively the experimental results can be quantitatively explained with kappa = 0 if an extra hydrodynamic coupling is included in the dispersion equation. From a physicochemical point of view this coupling may arise from the vicinity of the phase transition and/or molecular orientational effects promoted by the dilational wave. The small values of the dynamic elasticity, is an element of(omega), found in this work. can be rationalized in terms of a monolayer-subsurface material transport, within the Lucassen-Van de Tempel model.