A substantial amount of literature has shown that the input flooding and enhancement (Textual enhancement, TE) technique helps learners to perceive and acquire target features implicitly. Previous studies explored the efficacy of computer-assisted TE interventions in Second Language Acquisition with diverse techniques, but animation has not yet been sufficiently taken into consideration. In this paper, we developed an animation-based TE intervention to promote the primary school children' acquisition of the linguistic features of English question sentences. The results suggested that learners in experimental group improved their performances in producing questions and statements with a large effect size, as they were found to spontaneously put extra efforts in exploring the related knowledge of the visually enhanced forms. The study presumed that the animation-based TE intervention would stimulate participants' awareness and curiosity of the target forms, which consequently led to improved performance in tasks both involving precursor knowledge and newly acquired knowledge.