I'd like to know the difference of three sentences.
1. Spring has come.
2. Spring is come.
3. Spring is here.
Thank you in advance.
"has come" (1.) is the present perfect, and it expresses a continuum of time: starting from some unknown time in the past up until now the present time. "is come" (2.) is ungrammatical. There are too many verbs. The verb "is" takes a participle as its object; e.g., "is coming". Sentence 3. is a linking structure. "is" is a linking verb, and "here", a preposition in form, functions as an adverb.