You absolutely should be able to do that. If you know how to program another language, then a couple weeks of using the new language should get you the point of employment, and a couple months should put you close to where you were with the previous language (other than some of the rare esoteric stuff).
And employers know that, and (other than contracting work) they'll usually hire with the expectation of rapid training, and it's not an issue.
That hasn't been my experience. Most hiring managers I've had interviews with are in a hurry and want people with experience now. Good luck getting the job if you have to do a code screen against people with years of experience with that language.
And employers know that, and (other than contracting work) they'll usually hire with the expectation of rapid training, and it's not an issue.