In the 1870s, when Marx was already in his fifties, he found it important to study the situation in Russia, so he began to learn Russian. At the end of six months he had learned enough to read articles and reports in Russian.
“He said when people are learning a foreign language, they should not translate everything into their own language. If they do this, it shows they have not mastered it. When they used the foreign language, they should try to forget all about their own. If they cannot do this, they have not really learned the spirit of the foreign language and cannot use it freely.”