Teachers choose different ways to assess academic language knowledge, depending on the kind of information they seek about student learning. Typically, these assessments are composed of variations of assisted response. Students can demonstrate surface knowledge about given words or phrases by matching words to definitions. These items provide a great deal of assistance.
At a slightly more challenging level, providing a only the definition for which the student must recall the word provides a little less assistance. More challenging still is requiring students to complete sentences in which the target language has been used in the stem. This type of assessment allows a teacher to gauge student understanding based on the way the student completes the sentence. The assistance here is minimal, as the open response format requires that the student understand the appropriate context and syntax needed for a successful use of the word. Example: "In order to protect the powerless from the tyranny of the powerful, ___________________________________________." Any clause that describes an appropriate protection from tyranny will demonstrate student understanding.
However, if the goal is sophisticated usage, more complex performance tasks must be designed. Teachers set up opportunities for authentic use of newly acquired language both verbally and in written pieces. Measurement then, is based on appropriate usage in context and within the context of meaningful communication and accomplished with an observation guide or rubric. Two examples are shown below.
From Informal Reading Inventories and teacher-created tests, to observation guides and word maps, there are multitude of ways to assess vocabulary knowledge and growth. These two articles are well worth your reading time for a more in depth understanding: Contemporary Classroom Vocabulary Assessment for Content Areas and "Chapter 7: Assessing Vocabulary Knowledge - EdTech Leaders Online" (downloaded from courses.edtechleaders.org/documents/ elemvoc/assess_vocab.pdf).
Also worth a look: https://www.secondstorywindow.net/knowing-a-word-assessing-vocabulary/.