I would think that the specifics of the new language would (greatly) influence the difficulty. If the languages (known vs. new) are similar, it's typographical

I would think that the specifics of the new language would (greatly) influence the difficulty. If the languages (known vs. new) are similar, it's typographical more than anything else. How to make a code block, end statements, indicate arrays and pointers, etc. There's a vocabulary to pick up, but it should be like learning a new similar romance language when you're fluent in another. However, if the language paradigm is different, such as vector vs. scalar or other significant differences then developers can end up wrestling the language rather than working with in. I would suspect, as it was in my case, that the more experience one has, the worse this conflict will be. I had a way of approaching and implementing code that was just not what the language wanted to see. It was rather frustrating falling into the write/tune rather than write-then-tune process. My only "solution" was to first write things the way I had internalized and then revise them into the appropriate form(s) for the new language. Once this was done, and I would say it was a 3-6 month process, then the "normal" learning process started. Syntax, grammar and vocabulary is an ongoing process but it's easier as language familiarity grew.