Yanayin siffatawa wani nau'in jumla ne a cikin nahawu wanda ke ba da ƙarin bayani game da suna ko karin magana a cikin jimla. Ana kuma kiransa sifa clause saboda yana aiki kamar sifa ta hanyar gyara ko siffanta suna ko karin magana. Fassarar siffantawa yawanci tana farawa da dangin dangi kamar "wane," "wane," "wane," "wannan," ko "wane." Misali, a cikin jimlar “Littafin da na karanta jiya da daddare yana da ban sha’awa sosai,” sashe na “wanda na karanta jiya da daddare” jumla ce da ke ba da ƙarin bayani game da littafin.