Abstract：Star formation is crucial to the cosmos in many ways. Among the key questions in star formation, the birth of massive stars and the origin of stellar initial mass function are the two outstanding issues to be conquered. I will introduce how I have been tackling the two questions in Galactic molecular clouds at very different evolutionary stages, thanks to the recent development in mm/sub-mm interferometry and far-infrared imaging and polarimetry. I will discuss how ALMA can play a pivotal role in the study of outflows and protostellar cores. Such a study will be combined with an improved investigation of filaments with SOFIA and JWST. The synergy will potentially reveal a different picture of protostellar accretion and the origin of the stellar initial mass function.