In LIS, a preference for the omission of the indefinite article has been detected in younger signers. Instead of the manual sign one, young signers are used to indicate the indefiniteness of a noun phrase by means of non-manual markings. The most common non-manuals are backward tilted head and mouth corners down, as shown in the example repeated below.
indef
today skier ix1 see CL(curved open V): ‘zig_zag_ski’
‘Today, I saw a skier skiing with a zig-zag pattern.’