Requirements can be written so as no one can check if it is met. For example, one may write that a new system shall be better than the previous. But there is no criterion given that can help testing if it’s really so. In order to make sure that every requirement is testable we need to give it to test engineers for review. Additionally to reporting abovementioned cases testers usually come up with omissions, logical mistakes and inconsistencies in requirements noted as they do the review.
In general, review process is very effective as it helps eliminating issues before they are hard-coded into design and code.
All test engineers at EffectiveSoft are taught in doing requirement review. We have issues sophisticated internal guidelines and checklists to make sure that reviews are performed at a due quality level.