1. Introduction

On the basis of new achievements in topic research, this paper compares Chinese and Indo European languages to explore the types of topics in Chinese. The article proposes an upgraded topic type system and analyzes the relationship between Chinese topics and subjects. Thompson (1976) classified language into four types, but did not delve into topic diversity. Subsequent studies such as Chafe (1976) and Gasde (1999) classified topic types. In Indo European languages, argument topics are the focus of research and can be divided into two categories: topic based and left out of place. Bianchi u0026 Frascarelli (2010) distinguishes between contrasting topics and related topics. Other scholars such as Tsao (1990) and Xu Liejiong, Liu Danqing (1998) have classified topics from different perspectives. The topic type is closely related to the main clause phenomenon, which refers to certain syntactic components appearing only in the main clause. The expanding power of topics in Chinese leads to the emergence of multiple types, but the existing classification lacks theoretical generalization. This article aims to systematically examine the topic structure and main sentence phenomenon in Chinese, compare the differences between Chinese and Indo European languages, and adjust the Chinese topic classification system.

2. The Origin of Topic Categories and Topic Attributes in Chinese

The categories and attributes of Chinese topics consist of four major categories and 19 subcategories at the syntactic level, which are not commonly found in non topic first languages such as English. The topic component has the characteristics of unconventional positions, syntactic slots with inconsistent semantic relationships, referentiality of definite or categorical references, and the ability to carry topic tagged particles.

3. The main clause phenomenon and the topic of Indo European languages

Foley U0026 Van Valin (1984) proposed that subordinate clauses lack independent language power, resulting in certain components such as the Chinese modal particle "ma" not appearing in the clause. There are differences in the syntactic environment of the main clause phenomenon. Traditional adverbial clauses have strong independence, while the "clause" in Chinese complex sentences has stronger independence. Controlling verbs restrict the main clause phenomenon, while non controlling verbs are easier to accommodate. Lehmann (1988) pointed out that different languages use different means to express subordinate relationships between clauses, forming a hierarchical sequence from loose to tight. The tolerance of Chinese clauses towards topics varies depending on the language proficiency of the topic.

4. Re examination of Topic Categories and Main Sentence Phenomena in Chinese

The relationship between Chinese topic categories and main sentence phenomena is complex. Most topic categories can be used for various subordinate clauses without triggering the main clause phenomenon. But topics with tense words can trigger the main clause phenomenon, making it difficult to enter the object clause that controls verb dominance, and also limited in the attributive clause. Non controlling verbs do not prevent tagged topics from entering subordinate clauses. The subject verb sentence and subject verb sentence can be used as object clauses without adding a verb, but their qualification decreases after adding a verb. There is not much difference between left out topic and blank topic in Chinese, both of which can appear in object clauses, but it is not advisable to insert Titian words. Other topic categories such as superlative register, global register, verb register, subtopics, and disjointed topics are naturally used in object clauses and conjunctions, but the addition of tense words will reduce their qualification. The topic of identity is greatly limited by the main clause phenomenon, and most subcategories cannot enter the object clause, but under specific conditions they can. Repetitive sentences, concessions, contrasts, and emphasis on exclamation type identity topics are excluded by object clauses due to their strong language power. Adjective clauses are sensitive to topic particles, and most topic categories can be included in attributive clauses, but they mostly exclude Titian words. The topic sentence and the agent can generally be related, but the tense and aspect differences in the sentence may affect the qualification. Both register based and split based topics can be contextualized when semantically interpretable, but adding Titian words can affect their qualification. The situation where the topic of identity enters an attributive clause is slightly different from that of an object clause. A relative clause that extracts the subject from a verb is easier to establish than an object clause that controls the verb, but it is difficult to include a verb. The topics of concession, comparison, and emphasis on exclamation cannot be included in relative clauses. Overall, topics without particles are less restricted in the object clause and attributive clause of the controlling verb, while topics with topic particles are more affected by the main clause phenomenon and are clearly excluded, but they can still enter the object clause of the non controlling verb.

5. The main clause phenomenon and the attributes and systems of Chinese topics

In depth exploration of the attributes and systems of Chinese topics, as well as their relationship with the main clause phenomenon. Chinese topics are divided into two types: those with and without a topic. The former is closer to pragmatic topics and has stronger pragmatic functions and the ability to trigger the main sentence phenomenon. Chinese topics with tense words have stronger syntactic properties than English topics and are not limited by the scope of non controlling verbs. Topics without Titian words are highly syntactic and become basic syntactic components, allowing for free participation in syntactic operations. There is a significant difference in the frequency of occurrence between Chinese and English topics in natural language materials, indicating that the syntactic status of Chinese topics is more prominent.

6. Conclusion

As a topic first language, Chinese has a rich collection of topics and diverse topic attributes. Chinese topics usually do not trigger the main clause phenomenon and can be used as object clauses and attributive clauses. Unlike topics restricted by the main clause phenomenon in Indo European languages, they belong to syntactic topics. Chinese topics are divided into unmarked syntactic topics and marked grammatical pragmatic topics. Syntax topics can be transformed into grammar pragmatic topics, which is the process of their pragmatics. The subject, as a basic syntactic component, is also the default pragmatic topic, but sometimes it lacks topicality and excludes topic particles. When the subject is accompanied by a topic particle, it becomes an explicit grammatical pragmatic topic. The Chinese topic system includes: 1) syntactic subject - default pragmatic topic; 2) Syntax topics without Titian words; 3) Vocabulary with lexical topic markers - pragmatic topics; 4) Grammar pragmatic topics with topic particles. The first three categories can be transformed into the fourth category under appropriate pragmatic conditions. English only has pure pragmatic topics and vocabulary pragmatic topics, while some Indo European languages have diverse topic types but have not become syntactic topics.