I want to add the following: Verb forms like "is" or "have" can either function as grammatical words in English - IS, for example, is used in present progressive forms like " He is eating right now". "Have" has a grammatical function in sentences like "I have managed to get it done". There is no lexical meaning for IS or HAVE in this case. I would call them lexically empty. This is usually the case with respect to Aux.
IS or HAVE can show full lexical meaning in sentences such as these:
(1) John is a student (here IS means something like "equals" or "is equal to", IDENTITY).
(2) John has a car (meaning "John is the owner of a car", POSSESSION).
To get it right in a tree diagram, you need to determine first whether the word in question has full lexical or empty lexical meaning. I know Nepali a bit, and a verb like HO (the same as HAE in Hindi or Urdu) can actually have both occurrences as IS in English. Hope that helps.