Timmy's exposure to Cantonese and English began from birth. His father took sabbatical leave in the USA when he was three months old, during which time English tapes were played to Timmy. The primary caretakers in this period were Timmy's maternal grandmother, his mother and a Mandarin-speaking domestic helper. His parents took him to Los Angeles from age seven months to one year. He then spent the summer of 1994 in Canada, the UK and briefly in France. By the time regular audio recording started at 1;05.20, the live-in domestic helper was a Filipino woman who spoke fluent English. A trip to Australia was made at 3;01.17 and he visited his paternal relatives in England for three weeks at 3;02.28.

The parents followed the one parent-one language principle when addressing the child. The language between the parents is mainly Cantonese with a great deal of English mixed in, as is characteristic of the speech of Hong Kong middle class families. Despite the one parent - one language principle, the quantity of input from the two languages is by no means balanced: on the whole, Timmy had more Cantonese than English input in his first three years. The language of the community is Cantonese and the extended family (maternal grandmother and relatives) also speak Cantonese (and in some cases Chiu Chow). Regular input in English came solely from the father and the family's Filipino domestic helper, while English-speaking relatives visited only occasionally. In a number of recording sessions he showed a preference for using Cantonese, even when the research assistants tried to induce him to speak English.

In addition to Cantonese, Chiu Chow (or Chaozhou) was spoken by the child's grandmother and some relatives. The ancestral language of a sizeable minority in Hong Kong, Chiu Chow is spoken in eastern Guangdong province and belongs to the southern Min dialect group. Although diverging from Cantonese in many respects, it shares the broad typological characteristics which contrast with English. The child showed some passive knowledge of Chiu Chow but never produced more than occasional words.

The regular audio recording of Timmy took place between November 1994 and December 1996.The recording continued on a weekly basis until he was 3;06.25, except when he was away from home on a trip. Transcriptions are initially available on an approximately biweekly basis, as a number of tapes still await transcription. Unless otherwise stated, most of the files contain transcription of one side of the tape, i.e. about thirty minutes of recorded interaction between the child and other participants. Certain recordings are unusable due to various reasons such as technical failure of the recording instruments or failure to elicit the less preferred language on a few occasions. Timmy was reserved and sensitive as a child, which is reflected in some of his transcripts as he at times became taciturn.

The corpus data currently available via CHILDES for Timmy consist of 85 files, classified as (I) mixed (File nos. 1-13), (II) Cantonese (File nos. 14- 47) and (III) English (File nos. 48-85). The early mixed files involve natural interaction between the child, investigators and members of the family, without conscious prompting of either language. In these mixed files, a great deal of code-switching occurs during the course of conversation both on the part of the child and adult speakers. Subsequently, we tried to elicit one language at a time, e.g. in the first half hour of recording, English was spoken by one research assistant (RA) in order to elicit English, while the other RA used Cantonese in the second half hour to elicit Cantonese. The RAs who interacted with Timmy were all native speakers of Cantonese except Linda Peng Ling Ling, who is a native speaker of Mandarin and used primarily English in the later recording sessions. All the RAs speak English as their second language.

In practice, this one person -- one language strategy did not always work as intended for elicitation purposes. As a result one or more adults present at the recording may be speaking both English and Cantonese to the child who in turn code-mixes from time to time. Hence some files, especially the early ones under the category Cantonese, for example, actually contain a considerable amount of English and language mixing. As the child's languages develop, the division into Cantonese and English files can be made more easily. Spontaneous speech data were recorded at the child's home where the routines included activities such as role-playing, playing with toys and reading story books. The parents also kept a diary to supplement the audio-recording data. This enabled the researchers to address a wider range of phenomena, as certain structures (such as relative clauses) scarcely appear in the longitudinal corpus data (see Yip & Matthews 2000).

Sound-linked files

As a demonstration of how transcripts can be read and heard simultaneously using CLAN, a total of three sample audio files (two English, one Cantonese) linked to excerpts of transcripts are now downloadable via CHILDES.