I can barely make my myself understood in English. I was barely able to make myself understood in English. I can barely manage to make myself understood in English. I could barely manage to make myself understood in English. These four forms are correct. I think they are all self explanatory.

That is correct when talking about the past (past tense). "He asked me a question in English, but I could barely make myself understood." In the present tense, you would say: "I can barely make myself understood when speaking English." EXAMPLE: "We speak in English to each other, but I can barely make myself understood." An example of future tense would be: "I wish I could make myself better understood (by others)."