Marx was not a marxist and didn't think that communism was applicable for all the world. In fact he discovers an incongruence in the case of Latin America and dedicates to study it, for which I assume his knowledge of Spanish might have been useful. Marx was not the first one who explained how society may have started to work and how from the relationship to land different ideas of property, religion and politics developed. Durkheim has a lenghty explanation about the same in the Social Division of Work. But he does explain the nature of capitalism in its most economical dimension. He makes a parallel between liberty and economic exchange and in the Critic of the philosophy of law in Hegel (The capital is for sure his shortest title) he underlines the danger that represent capitalist values to the spirit of the human being. He proposes communism as the solution. Using the hegelian analysis of history (thesis, antithesis, synthesis) he determines that the next step after capitalism is communism. Yet, if the synthesis is going to be communism that obviously means that due to the cyclical character of history at some point it will become a thesis. and then what could become the antithesis of communism?
The communist proposal with its call for revolution has to be read in its specific historical frame. Marx had been inspired by the french revolution, from which he had underlined the separation between politics and religion, and believed it was an example to follow. Several times he criticizes the german intellectuals who philosophize but do not get involved in political action. He reveals in the capital the intricate fetishism of commodities. All this came to my mind because I wanted to talk about language. Language and Aldous Huxley. But now it's too late. I have to go to sleep.