The weak verbs, https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315620091/1e85dcd9-67fa-4282-a164-2a1659972fa7/content/inline2049.tif"/> which literally means 'sick verbs', are verbs whose roots contain one or more weak radicals, https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315620091/1e85dcd9-67fa-4282-a164-2a1659972fa7/content/inline2050.tif"/>. The weak radicals are the semivowels https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315620091/1e85dcd9-67fa-4282-a164-2a1659972fa7/content/inline2051.tif"/> /w/ and https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315620091/1e85dcd9-67fa-4282-a164-2a1659972fa7/content/inline2052.tif"/> /y/. They are called 'weak', because they are dropped or assimilated with vowels according to certain rules in many conjugational patterns. The weak verbs are also called assimilated verbs.