TOEFL listening section is going to be anywhere from 60 to 90 minutes. There are going to be 2 to 3 conversations and there would be 5 questions for each conversation. There are also going to be lectures in the listening section of the TOEFL exam. There would 4 to 6 lectures and there would be 6 questions for each lecture. As far as the grading is concerned, you will only be graded for 2 conversations and 4 lectures but the confusing part is that you would not know which conversations and lectures are going to be graded.