1 Introduction

The HCMC corpus of modern Chinese language was constructed using the COHA sampling method and hosted by Professor Shao Bin from Zhejiang University. Its aim is to truly reflect the century long development of modern Chinese language. HCMC is at the level of billions of words, covering multiple time periods of text, and belongs to a diachronic corpus selected in chronological order. The following text will introduce the current status of the development of the English Chinese diachronic corpus and the process of HCMC construction.

2 Development Background

The construction of a diachronic corpus needs to meet four standards: ordered time coverage, geographical coverage, sociolinguistic coverage, and genre coverage. The construction of the English language corpus has become relatively mature, with a capacity of billions of words and a time span of mainly one hundred years. The selection and sampling are balanced. European scholars started early in the development of English diachronic corpora, while American scholars have also achieved fruitful results, such as the ARCHER corpus and COHA. The development of Chinese diachronic corpora started relatively late, and strictly speaking, diachronic corpora are still rare, requiring reference from foreign experience. In recent years, Chinese scholars have created some Chinese language corpora at the level of millions or even billions of words, such as the Peking University CCL corpus and the Beijing Language and Culture University BCC corpus, but there are problems such as vague staging and lack of consideration for balanced sampling. Some new Chinese diachronic corpora, such as the "1920-2020 Centennial Chinese diachronic Corpus", have made improvements in sampling, but still have problems such as small scale and lack of continuous sampling. Compared with the English diachronic corpus, the Chinese diachronic corpus needs to improve its balance and representativeness in terms of material selection and sampling.

3. Development of HCMC

HCMC is a 100 million word modern Chinese chronological corpus, based on the COHA sampling scheme, aimed at reflecting the development of modern Chinese over the past century in a balanced and representative manner. The corpus includes language materials from 1920 to 2019, with approximately 10 million words per decade, totaling about 100 million words. The initial plan was to collect language materials from four language domains, but due to the mixing of magazine language materials and insufficient quantity, this language domain was abandoned. The proportion of language materials is 50% for news, 30% for novels, and 20% for non novels. The sources of language materials include "Republic Daily", "Ta Kung Pao", "Shen Bao", "People's Daily", etc. The language materials for novels refer to multiple literary award books, while the language materials for non novels include academic monographs, etc. The authors of the text have diverse geographical and socio-cultural backgrounds, and do not include texts from Hong Kong, Macau, Taiwan, or overseas Chinese authors. The word count of each language corpus in each ten-year period is allocated proportionally, and texts with less than the average word count are included in full text. The original corpus is cleaned and annotated with metadata, and word segmentation and part of speech tagging are performed using Python programs and Hanlp2.1.0b52 toolkit. HCMC features include large corpus size, balanced sampling of time periods and domains, provision of part of speech tagging and meta information. It can be used for research on the variation and evolution of Chinese vocabulary, syntax, and pragmatic features of discourse, as well as for comparative studies between Chinese and English over time corpora.

4 Conclusion

This article introduces the current status of the English Chinese diachronic corpus, emphasizes the importance of developing Chinese diachronic corpora, and points out that the development of Chinese diachronic corpora in China is still in the exploratory stage. It is necessary to learn from foreign experience, create large-scale, reasonably sampled, and highly representative Chinese diachronic corpora, in order to promote the development of diachronic corpus research in China. The School of Foreign Languages at Zhejiang University has a tradition of corpus construction. The late Professor Xiao Zhonghua created the Lancaster Chinese Corpus and the Zhejiang University Chinese Translation Corpus. The development of HCMC is a continuation and tribute to Professor Xiao Zhonghua's work.