男兒當自強 is the title of the main theme in wong feihong, i was told its translation is "a man has to stand one's ground", i do not know how verbatim this translation is. 男兒 is man, 自強 is either "his strength" or "from strength", i am not sure about it. As for 當, i am totally clueless what its meaning is.
What would be a verbatim translation? Who can explain the parts in the light of grammar?