Types of Weak Hadith

Question:
How many types of weak hadith are there?

Answer:
Weak hadith has types; al-Hafiz Ibn Hibban divided them into many types, mentioning that they number forty-nine. However, in reality, they are divided into two categories: weak hadith that is considered hasan (good) by al-Tirmidhi and a group of scholars, and weak hadith that is not considered valid and does not serve as proof due to its extreme weakness. This is the case if it contains a narrator accused of lying, or one who is grossly erroneous, or if it contains a break or is mursal (missing the Companion link) with no supporting chain or corroborating narration, or something similar.
As for hasan in the terminology of Abu 'Isa al-Tirmidhi (may Allah have mercy on him), it is: that which has slight weakness in the precision of its narrators, comes through two or more chains, and does not contain a narrator accused of lying, nor is it anomalous, broken, or defective with a serious defect. This is used as proof, like sahih (authentic) hadith, according to the scholars.
The early scholars divided hadith into two categories: authentic and weak, including the good in the authentic. Then al-Tirmidhi and a group after him saw it divided into three categories: authentic, weak, and good. So, for them, the good is what has slight weakness in the precision of its narrators, provided the other conditions are sound, such as integrity, continuity, and the absence of anomaly or defect. This is used as evidence, and it is better than opinions and analogical reasoning, as Imam Ahmad (may Allah have mercy on him) said.
A weak hadith that is structurally sound is suitable for use as proof and is better than human opinions; because its chain is continuous, it is not defective, and it is not anomalous, except that its narrators, or some of them, are not of perfect memorization. Rather, they have a deficiency in memorization and are not grossly erroneous, but they have illusions and mistakes.