新加坡以英語為主要家庭用語的華族家庭有逐年上升的趨勢。為了更好地瞭解新加坡兒童的華語能力和語言使用情況，新加坡華文教研中心展開為期兩年的研究──《新加坡華族兒童語言環境及語言使用調查》。研究項取樣自新加坡學前中心，共有1,233 名6 歲兒童的父母參與問卷調查，當中372 名兒童參加了圖片描述測試和認字測試。本文旨在探討家庭語言環境對新加坡6 歲華族兒童詞彙能力的影響。本文選取了11 名來自雙薪家庭、除幼稚園老師外無其他照顧者的兒童，並將它們分為三組──以華語為主要家庭用語、以華語及英語為主要家庭用語和以英語為主要家庭用語。兒童圖片描述測試的視頻或音頻，以CHAT 模式轉寫，並以CLAN 系統分析其詞頻、詞種、和平均句長。研究結果顯示，三組來自不同語言背景的11 名新加坡華族6 歲兒童的詞彙能力，在詞頻上沒有顯著區別，但是家庭用語對詞種和平均句長有顯著影響，功能詞的缺失，使得他們難以將所習得的詞彙組詞成句。

With English language dominating social use in Singapore, there is a rising trend of English being the dominant home language in local Chinese families. To better understand children’s Chinese language ability and their language exposure, the Singapore Centre for Chinese Language conducted a 2-year research project entitled “An Investigation of Singaporean Chinese Preschoolers’ Language Use & Exposure”. A total of 1,233 parents of Kindergarten 2 children (aged 6) participated in a survey, and 372 children of these 1,233 parents subsequently participated in a picture description and a character recognition test. This paper aims to examine the effect of home language on the Chinese lexical ability of 6-year-old Singaporean Chinese children. Eleven children from dual income family were selected and divided into three home language groups: CHL (Chinese as main home language), CEHL (Chinese and English as main home languages) and EHL (English as main home language). Video- and audio-recordings were transcribed by using CHAT transcription. Word types, word tokens and mean length of utterance were analyzed by CLAN program. Two-way ANOVA analyses with home language and gender as independent variables were performed separately on word types, word tokens and mean length of utterance. The results reveal that lexical ability of the 11 6-year-old Chinese children has no significant difference across three home language groups in terms of the lexicon acquired. However, home language has significant effect on word type and mean length of utterance. The lack of function words causes them problems in putting words together.