Is a mnemonic approach a critical success in remembering new vocabulary words in contexts cause my cousin when he is reading a book where it consists of real information not just a random singular word but full paragraphs he reads a few pages and each time he finds a full sentence which he does not understand he translates and puts it on anki droid flashcard with pictures now i want your suggestion whether it is a good way to learn or not cause a learning is a forget and learning process and we are always about to forget new words it's obvious.

It really depends on the person. Personally for me, when I come across a sentence in which I don’t understand I look at the words I do know and rely on context clues to help figure out the words I don’t. I was always taught this way and prefer this way as it helps me learn the meaning of the word individually rather than the sentence as a whole which may prevent you from adding those words to your vocabulary. Really all it’s doing is teaching him the phrase and not the words (and the translators are sometimes incorrect). While it may seem helpful, until he figures out how to use context clues to learn each word then he won’t really be expanding his vocabulary. Phrases are good to know but if you don’t have an understanding of the grammar and set up then you won’t be able to put other words in that format or use those words in other phrases. Sometimes there are even grammatical phrases that change the meaning of the sentence in some languages so learning the phrase doesn’t teach you the meaning as a whole, just in that instance.