Difference between 谦虚 and 虚心? In my Chinese textbook, 谦虚好学 is used, and 虚心求教 is used as well. They both mean modest, so when should I use each one?
謙虛好學 means be modest and loves learning. 虛心求教 means be modest and appeals others to teach. To verified this you can search 謙虛 in dictionary owned by Ministry of education in Taiwan. It shows the description 虛心謙讓不自滿。(modest). In the dictionary 好學 described as 喜歡學習。(love learning). In the dictionary 虛心 described as 謙退容物，心不自滿。(modest). In the dictionary 求教 described as 懇請他人指教。(appeal others to teach).

Use quotation marks you can find tons of example on google for example: "謙虛好學" and "虛心求教" google search engine do show you that how much data it found. If there are so many people use this way it is more reliable. You can determine the reliability of usages.