Having gone through ups and downs, John and Tom are now good friends.
"having gone through ups and downs" is said to be a participle clause, but it has neither a subject nor verb.
Are we having a trend of doing away with phrases?
Hello, Cindy, and welcome to the Grammar Exchange.
To add a couple of further remarks to what Gustavo has already explained, I wanted to assure you that "having gone through ups and downs" does indeed have a verb. It has two verbs, actually: "having" and "gone."
"Gone" forms part of the phrasal verb "go through," which is in its past-participial form. "Having" is the present-participial form of the auxiliary "have" that we have in "John and Tom have gone through ups and downs."
It's true that "Having gone through ups and downs" lacks an overt subject. It has an implied subject. In formal syntax, that implied subject may be represented as a silent pronoun (PRO) co-referent with a phrase in the matrix clause.
When you ask, "Are we having a trend of doing away with phrases?," you are presupposing that clauses are not phrases. But clauses are phrases. A phrase can be realized by a single word, by a group of words, or by an entire sentence.
To help you see that the implied subject of the participial phrase/clause (which is a "free adjunct") in your example is "John and Tom," you may find it helpful to know that we can add that subject overtly. This is an "absolute construction":
- Tom and John having gone through ups and downs, they are now good friends.