1. Data: The construction 'lah !' exhibits significant frequency variation across the dialects in the GloWbE corpus. It is prominently used in Singapore and Malaysia, where its normalized frequency is substantially higher than in other countries. Singapore has the highest frequency, closely followed by Malaysia. In contrast, it is nearly absent or extremely rare in Western English-speaking countries like the United States, Canada, Great Britain, and Australia, as well as in South Asian and African countries, where the frequency ranges from zero to very low. A few countries, like Ireland and India, show minimal use, but these frequencies are negligible compared to Singapore and Malaysia.

2. Possible explanation: The notable frequency of 'lah !' in Singapore and Malaysia can be attributed to its roots in the local colloquial vernacular, often referred to as Singlish and Manglish, respectively. These dialects incorporate elements from various languages, reflecting the multicultural and multilingual nature of these societies. 'Lah' is a discourse particle borrowed from Chinese dialects such as Hokkien and Cantonese, and it functions to convey emphasis, assertiveness, or camaraderie. Its frequent use in Singapore and Malaysia indicates its role as a distinctive feature of local English, integrating cultural and linguistic identity. In contrast, Western and other English-speaking countries lack this linguistic influence, leading to its rarity there.

3. Competing constructions: In dialects where 'lah !' is infrequent or absent, speakers might use alternative discourse particles or pragmatic markers to achieve similar communicative functions. For example, in American or British English, expressions like "you know," "right," or "okay" might be used to add emphasis or seek agreement. In Indian English, particles such as "na" or "yaar" could serve similar purposes. These alternatives fulfill the same communicative roles, adapting to the linguistic norms and cultural contexts of each dialect, hence the low frequency of 'lah !' outside Singapore and Malaysia.