Phonological awareness tests the child's ability to recognize sounds. Sounds are the basis for reading so working with the preschooler to determine if he can identify things such as rhyme determines the current skill level of the student. Teachers can read pairs of words and see if the child correctly identifies rhyming words or a word can be read and the student must come up with another word that rhymes. Rhythm is also important and helps identify syllables. Identifying similar sounds in a group of words assesses a student's ability to deal with different types of input. Read a small list of words such as; fix, fall, fun and then ask the student to identify the similar sound in all the words.
Fluency tests for preschoolers deal with letters. In order to determine how well a child knows his letters requires providing a chart of letters not in the correct order. Going over the chart with the student gives the child the opportunity to name the letters as you point to each one. Another assessment takes letters a step further by going over the sounds individual letters make. It is important to test the child with the letters out of order as saying the alphabet is a memorization tool and does not work the same as reading.
Preschool vocabulary is limited. In order to assess the level of the child, you should sit with the student and ask him to define words in his own vocabulary. You can run the test over various types of words in order to determine how many words the student actually knows. It helps to have a set vocabulary list you wish the preschoolers to begin with in order to compare all the students on equal ground. If some students are performing better than others you can begin to work with prefix and suffix analysis as well.
Comprehension for preschoolers involves reading small paragraphs or sentences and asking questions. This allows you to determine how much the student is retaining as well as how well he understands contextual tools. As the preschooler advances, contextual clues will become easier for him to understand, but the initial assessment should be done so you can mark the progress as the year progresses.