If you are an adult English language learner, repeat, repeat and repeat what you want to learn.
Adult English language learners usually do not like to use repetition to help them learn the language. Why? Adults are very intelligent. They are very cultivated, and they are very aware of the world. Yet they seem to make the mistake that if they understand the language intellectually, they have also learned how to speak the language. However, this is far from true. Doing is very different from knowing. That is why many adult learners keep making the same grammar mistakes, keep sticking with the same simple vocabulary and also make the same pronunciation errors—and for years! They are personally very frustrated in their language learning because they are progressing so slowly. All of these problems could be solved very quickly by simply repeating over and over the things that they want to learn. Yet they rarely do it.
Think about vocabulary first. It is a known fact that a learner has to encounter a word many times before he or she actually starts to use it. How many times? Perhaps ten times or more. That is according to studies actually done with real learners. Also, it makes sense. I know myself that when learning a language if I hear a new word once and do not hear it again for a long time, I am unlikely to remember it, let alone use it. Also, the older you get, the more likely that the words will slip away into the unconscious. Now, a very young learner might remember a word after hearing it just once or twice. Their memories are so much better. They soak up language like little sponges. Adults, however, do not have the same mind capacity.
The easiest way to repeat vocabulary words is just simply to read many books. Many books are written just for second language learners. They have a controlled vocabulary and are graded into levels, such as elementary, intermediate and upper-intermediate. I think this is the most fun way to repeat vocabulary. You, the reader, will already know 95-99% of the vocabulary so you will be reinforcing all your existing vocabulary in a very entertaining story or topic. You will not have to use your dictionary when you see a new word. You can just guess at its meaning and move on, reading rapidly and enjoying the experience. With this method, you will also be learning the grammar without even thinking about it, just like a native speaker does when he or she grows up in an English-speaking country.
Of course, there are other strategies. You could make flash cards—index cards with English on one side and your home language on the other side—to flip through to repeat your vocabulary. You could also make your own small dictionary. Put words in it that interest you or that you would like to use. It’s your dictionary! Translate each word into your own language and use it in a good English sentence. When you have free time, just read your sentences aloud, one after the other. Another way to repeat words and model sentences is to simply read articles, texts, stories, dialogue and so forth that you study in your English class, that is, if you are taking a course. Most students totally forget every bit of material that they are given in a classroom sentence as soon as they leave their class. Actually, that material becomes very valuable as soon as you have studied it. It is much more valuable after you have studied it! After you are familiar with it, you can use it to practice the language—practice your pronunciation, practice your grammar and reinforce your vocabulary. All you have to do is read it aloud, over and over again. Repeat, repeat and repeat…and next time you have to speak or write, you will deliver beautiful sentences.
The first thing that should occur to an adult learner of English is that if they are finding it hard to produce good sentences easily is that they have to repeat words and sentences so that they can produce those sentences easily. Why not? This action is very natural, isn’t it? It is like learning to play tennis. If you cannot hit the ball over the net easily, you just have to keep hitting that ball until you can get it over the net. Too often, when adults learn language, they do not look at it as a simple skill that they have to learn. Actually, I have never seen an adult learner who was willing to repeat vocabulary words, sentences and structures, that could not learn the language quickly and effectively. If you are an adult, you have to use your adult strategy and power to succeed. Let children have their power; however, you use your power too!