Is the Hadith of the individuals narrated by continuous testimony from those other than the Companions, or not?

Scholars divide narrations into mutawatir (mass-transmitted) and ahad (singular). Mutawatir is what is narrated by a large group, making it impossible for them to conspire on a lie. Ahad is what falls short of that, and it does not have a specific number. An ahad narration may attain tawatur in some layers of its chain of narration, or it may not, like the hadith "Actions are but by intentions," which was narrated by a single narrator in most of its layers, while it was mutawatir from Yahya ibn Sa'id. The chains of a hadith may multiply after the Companion in varying degrees, like the hadith "When one of you comes to Jumu'ah, let him perform ghusl."

The soundness or evidential weight of a hadith is not conditioned on the multiplicity of its chains. Rather, the authenticity of many hadiths in the two Sahih collections is affirmed even if some of their narrators were singular, and certainty of a hadith's authenticity may be achieved through other corroborating factors besides number. Likewise, the multiplicity of chains does not necessitate the authenticity of a hadith; for the weakness might be so strong that it is not removed by the multiplicity of chains. For acting upon a hadith, it is sufficient for one to have strong probability of its authenticity if certainty is not attainable, for the people of knowledge have unanimously agreed on accepting and acting upon the singular narration of a just person, if it is established.