A linking verb connects two parts of a sentence. Auxiliary verbs are used to create complex tenses, such as future perfect continuous (will have been going - where <em>will have been </em>are all auxiliary verbs). Intransitive verbs are intransitive - they are not linking. So, having this in mind, the most common linking verbs are various forms of be. For example: She <u>is</u> very tall.
Always keep just one idea on note cards when doing research to prevent jumping from topic to topic and from question to question thus making it incoherent and incohesive.