(1) Modifying prepositional phrases with very needs degree meaning and is unusual
The adverb very modifies expressions that can take on different degrees, i.e. whose semantics allow for a scale on which a concept can be compared. We can test for the presence of degrees with a paraphrase such as "to a certain degree." When a prepositional phrase allows for a degree interpretation, modification with very is marginally acceptable.
(1) they are actually very, very in love. (2013, spoken English, NBC: Today Show)
(because paraphrase works: They are in love to a certain degree.)
(2) * They are actually very, very in London.
(because paraphrase doesn't work: ??He is in London to a certain degree.)
(3) I'm very in favor of more torpedoes. (2004, Bk: Wildfire, written English)
(because paraphrase works: I'm in favor of it to a certain degree.)
(4) * I'm very in front of a torch.
(because paraphrase doesn't work: ??I'm in front of it to a certain degree.)
(5) So, yes, I'm very for it (2002, CNN_Chung, spoken English)
(because paraphrase works: They support it to a certain degree.)
(6) * I'm here very for my colleague
(because paraphrase doesn't work: ??I'm replacing my colleague to a certain degree.)
However, prepositional phrases are generally taken to express states. Speakers usually use them to convey an idea that can be true or false with no degrees in between. One is either in love or not, in London or somewhere else, for something or against something, etc. Therefore, very does not normally modify prepositional phrases.
To support this, I browsed the Corpus of Contemporary American English for five common prepositions, in, on, of, for and about and counted how often they are preceded by very in comparison to very much. The results are shown below:
(Figure 1: use of very (vs. very much) + preposition in contemporary English)
The graph shows that prepositional phrases occur with very only very rarely, between 0.2% and 6.4%.
- So, to answer the question: as a rule of thumb, very does not modify prepositional phrases, but it may sometimes do so if the prepositional phrase conveys a degree interpretation, rather than a true-or-false state.
(2) The preposition like is special – it derives from an adjective
Originally, the word like functioned as an adjective in English. There are many ways to show this. Here are two adjectival characteristics that like used to possess.
(a) The word used to be inflected like any other adjective. For example, the following Old English example has the word gelicestan, literally like-est – the superlative of the adjective like ‘most like, most similar to.’
(7) þa funde he oðerne [...] him þone gelicestan,
then found he another one him the like-est
‘He found then another one who was most similar to him’
(Old English Bede, 4:23, c. 880 A.D.)
(b) The adjective could also be nominalized. That means that you could turn the adjective into a noun just like you can turn poor or blind into a noun today (The poor are suffering, The blind leading the blind). The meaning would be something like ‘those who are like you, fellows, comrades’ (cf. ilk).
(8) þine gelican
(Aelfric’s Life of Saint Eugenia, c. 1000 A.D.)
Over time, the word like came to be distributed like prepositions. Again, there many ways to demonstrate this, but I will only mention two arguments.
(a) As an adjective, like occurred almost exclusively with copula verbs, like be. But nowadays phrases with like can easily modify other verbs. Hence, expressions like he swam like a fish, he worked like a maniac, she dressed like a princess etc. used to be impossible but have now become quite common. One of the earliest examples of such modification I found, shown below, is from 1529. The OED (sense B.1.a(a)) lists the earliest date as c1390(a1376).
(9) he dyd live like a wyddower / whiche a fore tyme had bene maryed
(Desiderius’ An Exhortation to the Diligent Studye of Scripture, 1529)
(b) The word like can now be used to introduce a list of typical examples, meaning ‘such as’. The OED (sense D.2(a)) records this usage from 1593 on.
(10) i am acquainted with a sort of men like him
(Voiture’s Letters of Affaires Love and Courtship, 1657)
So, to summarize, the word like is slowly losing adjectival properties, such as adjectival inflection or nominalization, and slowly gaining prepositional uses, like verbal modification or listing of typical examples. Modification of like with very is just another of its adjectival features.
It follows that:
(i) Since like derives from, and retains some properties of, an adjective, modification with very is far more common for like than for any other preposition.
(ii) Since like is in a century-long process of losing its adjectival features, modification with very is slowly dropping out of use.
To demonstrate this, I collected some data from the Corpus of Historical American English. I compared the frequency of very like to very much like over time, as illustrated in the pairs of examples below.
(11)a. Thou'rt very like her, that's certain (1822, LoganAFamilyHistory)
(11)b. that is very much like him. (1835, ClintonBradshaw)
(12)a. being, in the shape of his body and limbs, very like a frog (1823, ErrataTheWorks)
(12)b. begin to feel myself very much like a fish out of water (1835, AnOldSailorsYarns)
(13)a. you are very like your father (2006, Distraction)
(13)b. You look very much like my son at your age (2000, RulesSurrender)
(14)a. He had her pale hair, a face very like hers. (2001, FantasySciFi)
(14)b. Mrs. Townsend or someone very much like her. (2004, Hallelujah!Welcome)
I also collected the same historical data for the preposition in. The graph below shows the percentage use of very (vs. very much) for every decade from 1810-2000.
(Figure 2: Historical development of very like and very in)
As the graph shows, (i) modification with very occurs overwhelmingly more frequently for like than for other prepositions like in, by a factor of more than 20, and (ii) modification of like with very becomes less common over time, from 60-70% in the early 1800s to about 10-20% today.
- Hence, there is a secondary answer to the question. The preposition like in particular is much more likely to permit modification with very, especially as you go further back in time, as in Shakespeare’s very like a whale, because like derives historically from an adjective.