I've learned that the two most important tools in my ESL bag of tricks are patience and humor. Many students learning a second language are self-conscious-- it's even tougher for those students who have a naturally shy disposition. But I found that these two qualities helped two of my best students in Korea, who seemed terrified of speaking to me the first time I met them. One student was female and 11 years old. The other was a 22 year-old male who had just returned to school following his time served in the Korean army. Although it took them many long minutes to answer questions at first, they had both made significant progress at the end of six months, and my older student had advanced from a beginner to high intermediate speaker. They understood the jokes that I made in English, and they were able to make jokes themselves that set the entire class laughing, which is a huge confidence booster.
Korean education emphasizes grammar over conversation, but you need both to become fluent. Korean students have been trained to work hard and consistently, and these two characteristics are fundamental to making progress. You simply won't advance in learning any language, unless you make the time every day to study the vocabulary or grammar. It was no surprise to me when we reviewed the homework and found that my students almost always had the right answer. But you also need to practice speaking out loud with a buddy. Hearing the target language spoken, especially by a native speaker, and speaking it develop the memory muscles we need to advance in comprehension. When I asked questions in class, I made sure to specifically ask these students, who could easily blend into the background, questions that involved multi-word answers. For instance, "Who is your favorite Korean pop singer and why?" or "What is a typical Korean date?"
Sometimes, other Korean students would get impatient, and attempt to answer for them. Sometimes, I had to think for a minute and repeat their answer to them to make sure I understood. But no matter what, I found that they developed confidence when I let them finish their sentences with only a little help from me. I could make corrections to their grammar by writing their answers on the board and asking them to repeat them correctly, but the important step was to gain their trust by allowing them the time and space to practice speaking.