I think they are making a sandcastle. ... Cause they aregg g holes and stuff like that and they have like the shovels and... yeah. Which of the following features of the student's interlanguage is most evidently still in development?

Causative constructions are not prominently featured in the student's speech, but there is no clear indication of their current proficiency level. The student's statement does not demonstrate any use of causative forms, nor do they seem necessary for conveying their intended meaning in the context provided.

The student's speech does not include explicit examples of contractions, yet the absence of these forms does not significantly hinder comprehension. The focus is more on the clarity of their statements rather than the use of contracted forms, indicating that this aspect of language may not be a priority in their current development.

While the student may show some understanding of verb tenses, their speech is primarily descriptive and does not demonstrate a complex range of tense usage. However, the use of simple present tense in their description suggests they have a basic grasp of tense, which is not as underdeveloped as their ability to form relative clauses.