The GRE revised General test is administered as a computer adaptive test, but not all sections are adaptive. Each of the verbal and quantitative assessment portions of the exam has two parts. For both of these assessments, the first part is NOT computer adaptive, while the second is.
The first of the two sections for the quantitative and verbal assessment portions of the GRE exam have questions that ETS has calculated will be answered correctly by approximately one-half of the people who take the test. Based on how well you do on the first section of the two assessment sections, you will be provided with question that are of appropriate difficulty on the second section.
For example, if you answer all questions correctly on the first section of the verbal assessment, then the questions that you'll see on the second verbal section will be difficult. Likewise, if you answer incorrectly most of the questions on the first section of the quantitative assessment portion of the exam, then you'll be prompted with easier question on the second section of the quantitative assessment portion of the exam. Based on your performance on the first sections of the verbal and quantitative assessment portions, the computer will select question for the second section that it thinks you have approximately a 50% chance of answering correctly.
Don’t worry about trying to figure out if the current question that you are trying to answer is easy or hard – just be sure to do your best. Even if you do know if the question is hard or easy, does it really matter? You have to answer the question that is presented to you, so it is irrelevant whether the question is difficult or easy.