First, a conventional and grammatical phrasing would be:
I like (or enjoy) sports, mainly swimming and running, and spending time with friends and family.
That is how I'd write it. In general, position the item that you wish to emphasize at the end.
Sports, especially swimming and running, and enjoying my friends and family.
Keep the elements grammatically concordant; for example, both of them noun phrases. Sports ... is a noun phrase, but meet needs to be changed to an -ing form to be a noun phrase.
Is it grammatical/acceptable?
Meet friends and family.
is probably not acceptable or grammatical in this context, or is marginal, because it's not what we expect in relation to the heading (interests and hobbies).
Most would probably say that the sentence is grammatical, on its own, but doesn't, in this context, mean what you intend, and does work as a matter of style.
I disagree with the common idea that grammar describes nothing larger than a sentence, however, so I'd personally say it's ungrammatical.
Explaining why is a bit tricky. Here's my amateur analysis:
We will likely read the heading as representing part of an implied expanded sentence:
My interests and hobbies are: ... [something]
The something is a complement and is expected to be supplied after the heading.
If it were an ordinary sentence, not split between heading and list, we would have the structure, if we simplify it:
[Some things] + [are] +(complement).
Let's further simplify it by making it singular, and include someone as an alternative. It may make the illustration more clear:
[Something or someone] + [is] +(complement).
Logically, the verb be here often functions like an equals sign. It is a copula. In many traditional or elementary grammars it's called a linking verb.
Meet, in your sentence, is a verb. Verbs don't work as complements to a copula:
- OK: Something is wrong. (adj)
- OK: Mary is tired (adj)
- OK: My favorite drink is whiskey (noun phrase)
- OK: Sam is outside (adverb or adverbial)
- OK: The fly is on the window (propositional phrase/adverbial)
- *Something is eat.
- *Someone is walk.
- *David is swim.
- *The bird is sing.
- *Jens is meet.
- *Jens and J.R. are meet me.
- *My hobby is meet them.
None of these are grammatical because they try to use a verb phrase as a copula complement.
The issue of -ing forms is complex and confusing with respect to this issue. In brief, when we have
The bird is singing.
Is functions not as a copula, but as an auxiliary to the present continuous verb singing.
In My hobby is meeting my family and friends, is does function as a copula, but meeting functions as a noun heading a noun phrase. Thus it is grammatical. However, that utterance would be odd to native English speakers, because of the connotation that meeting tends to convey in that context.
My hobby is swimming is felicitous, with is functioning as a copula and swimming as a noun (some say gerund, some say verbal noun).
The Wikipedia entry cited above lists the type of word classes or sentence parts that are normally permitted as complements following a copula:
The predicative expression accompanying the copula, also known as the complement of the copula, may take any of several possible forms: it may be a noun or noun phrase, an adjective or adjective phrase, a prepositional phrase (as above) or another adverb or adverbial phrase expressing time or location.
Meeting My family and friends
Meeting my family and friends
could be grammatical and acceptable, if we present it as an element of a list.*
The reader would interpret the heading like, for example,
[I enjoy the following activities:] Meeting friends and family, singing in the bathtub, drinking heavily before work, etc.
When can we omit subjects from a sentence?
Many sentences don't contain a subject. Really.
Really, above, is an example.
Most dictionaries say that sentences typically contain a subject. Implying that some do not.
Implying that some do not, above, is a sentence that contains no subject.
Me: Where did you go?
My friend: Haircut.
Haircut and handsome are both sentences. Neither contains a subject. Ugly would be a much more fun alternative. It would also be a sentence.
This dictionary definition is different from most:
A sentence is a group of words which, when they are written down, begin with a capital letter and end with a full stop, question mark, or exclamation mark. Most sentences contain a subject and a verb.
From Wikipedia's sentence (linguistics) page:
A sentence is a set of words that in principle tells a complete thought (although it may make little sense taken in isolation out of context). It may be a simple phrase, but it conveys enough meaning to imply a clause, even if it is not explicit; for example, "Two" as a sentence (in answer to the question "How many were there?") implies the clause "There were two."
The Wikipedia entry repeats the idea commonly heard in elementary school: A sentence is a complete thought.
This may feel satisfying, but if we include a conjunction, a sentence often contains more than one complete thought, like this one.
It qualifies the statement with in principle, suggesting we are swimming in murky waters.
It suggests that a sentence is (probably or somehow?) complete, but maybe not by itself. So, the Two, for example, is complete when it follows a How many? question.
What does complete mean if it needs something else?
The Wikipedia entry goes on to present a seemingly more straightforward alternative definition, essentially the same as that quoted above from the Collins Dictionary:
A sentence can also be defined purely in orthographic terms, as a group of words starting with a capital letter and ending in a full stop [period].
Following the above,
Dog car yellow while.
is a sentence.
This is not a completely satisfactory, either. Is STOP on a stop sign a sentence? What about Have a gd day as a text or chat message, with no end punctuation?
I suggest that the "real" answer is very complex, and that PhDs in linguistics continue to trade papers seeking to define what a sentence is.
Or actually, most linguists understand that sentences do not exist as real things in nature, but only represent our efforts to make sense of something that is complex (and evolving) beyond our present capacity to understand.
When definitions are given as if sentences were something real, we tend to feel comfortable with the illusion that we can describe the indescribable, or we feel frustrated and lost when we realize that our descriptions don't hold up under even a couple of layers of questioning.
More on the elusive quest of defining sentence:
A professor of linguistics on What is a sentence?
The following is one of the most sophisticated discussion I've seen on the problems with defining a sentence, by another professor of linguistics. He settles on defining it as a maximal clause, i.e. a clause that is not part of another clause. However, he goes on to say that we cannot find a good definition of clause and deems it a primative notion: one that's ultimately undefinable!
When can we drop subjects?
We have the same problem when we try to accurately define a subject. The linguist Geoffrey Pullum discusses the problems with commonly held definitions here, and indicates that subject can only sensibly be defined in syntactic and morphological terms: it (whatever it is) must agree in number with its verb, it can only be in the nomitive if it's a pronoun (I think, not **me think,* etc.):
"When can we drop subjects?" is probably not a useful question because the answers lead to more questions until they become metaphysical.
A better question is "Is this acceptable to others (other English speakers)?"
Then the answers might include:
- No (people don't talk/write that way).
- To speakers of some types of English, but not others.
- In some contexts but not others.
- It's of marginal/questionable acceptability.
The best way to learn how to write acceptably is to read a lot and listen a lot to the output of proficient speakers, and focus on the meaning of the messages instead of trying to analyze the forms of the language. Our brains, through unconscious processes, are better at figuring out "grammar" on their own, uninterrupted and not distracted by textbook grammar rules, which do not faithfully represent what proficient speakers know about how to use English. What we know but usually can't explain or describe.
Your sentence, if that's what it is, appears to be an element in a list. To determine if it's acceptable, conventional, or "good", we'd need to see how it fits with other elements of the list, how the list is introduced, and how it's formatted.
Because meet has different connotations, such as gather for business purposes, or emphasizes the moment of contact, spend/enjoy time with or some other phrase would probably better communicate what you want to say, and would be more conventional on a resume.