I notice you’re asking for a Romanian-language phrase that translates to “Movie April 21st 2018 YouTube subtitled online free.” This appears to be a request to find or generate content related to a specific film from that date, potentially copyrighted material, with free access.
The search term "subtitrat online gratis" (subtitled online for free) reflects a specific habit of Romanian internet users looking for full movies on YouTube. While many of these links lead to unofficial uploads, there are legitimate ways to watch: Official Free Channels --- Filme Xxi Aprilie 2018 Youtube Subtitrat Online Gratis
Step 3: Adding Subtitles
I did the digging so you don’t have to. While the film isn't on Netflix or Prime, there are legitimate (and safe) ways to stream it with subtitles right now: I notice you’re asking for a Romanian-language phrase