"Ce que" and "qui" are used in French to introduce relative clauses, while "nur que" and "qui" are used in German. In French, "ce que" is used to introduce a relative clause that functions as the direct object of the main clause, while "qui" is used to introduce a relative clause that functions as the subject of the main clause. In German, "nur que" is used to introduce a relative clause that functions as the direct object of the main clause, while "qui" is used to introduce a relative clause that functions as the subject of the main clause. **

"Que qui est ce que qui" is not a standard phrase in French. It seems to be a combination of different question words and does not form a coherent question. "Que" means "what," "qui" means "who," and "est-ce que" is a phrase used to form yes/no questions. However, the combination of these words in this order does not make sense in French. It is possible that there was a mistake in the original question or that it was a typo. **

We use "ce qui" when the subject of the verb is unknown or unspecified. "Ce que" is used when the object of the verb is unknown or unspecified. "Qui" is used as the subject of the verb, while "que" is used as the direct object of the verb. "Dont" is used to indicate possession or relationship, and "lequel" is used to refer to a specific noun that has been previously mentioned. **

Qui quae quod is a Latin demonstrative pronoun that means "who," "which," or "what." It is used to refer to people, things, or ideas in a relative or interrogative context. In English, it can be translated as "who," "which," or "what," depending on the context in which it is used. **

One can abbreviate 'que qui' by using the abbreviation 'qq' in written communication. This abbreviation is commonly used in French to represent both 'que' and 'qui' in a more concise form. It is important to note that using abbreviations like 'qq' may be informal and should be used appropriately depending on the context. **

"Ce que" is used when the relative pronoun refers to an abstract idea or an entire clause, while "que" is used when it refers to a specific thing or person. For example, "Je sais ce que tu veux" (I know what you want) and "Je sais que tu veux partir" (I know that you want to leave). On the other hand, "ce qui" is used when the relative pronoun refers to the subject of the following clause, while "qui" is used when it refers to the subject of the main clause. For example, "Ce qui m'étonne, c'est qu'il soit parti" (What surprises me is that he left) and "La personne qui m'a aidé" (The person who helped me). **

In French, "qui" is used as a subject pronoun to refer to people or things that are the subject of the sentence. On the other hand, "ce qui" is used as a subject pronoun to refer to abstract ideas or concepts that are the subject of the sentence. For example, "Qui est-ce?" means "Who is it?" while "Ce qui est important, c'est de réussir" means "What is important is to succeed." **

In French, "ce qui" is used to introduce a subject or topic in a sentence, while "qui" is used as a subject pronoun. For example, "Ce qui m'intéresse, c'est la musique" (What interests me is music) uses "ce qui" to introduce the subject of the sentence. On the other hand, "La personne qui chante est ma sœur" (The person who is singing is my sister) uses "qui" as the subject pronoun referring to the person singing. **