The AHD 4 produces one entertaining page on the word 'get.' It helped that I
had met many of its meanings as transitive and intranstive verbs and its
phrasal verbs and idioms. I especially enjoyed the usage notes at the end
which solved a couple of long-standing puzzles that I did not know even how
to phrase.
The use of 'get' in the passive, as in 'We got sunburned at the beach,' is
generally avoided in formal writing. In less formal contexts, however, the
construction can provide a useful difference in tone or emphasis, as between
the sentences 'The demonstrators were arrested' and 'The demonstrators got
arrested.' The first example implies that the responsibility for the arrests
rests primarily with the police, while the example using 'get' implies that
the demonstrators deliberately provoked the arrests.
In colloquial use and in numerous nonstandard varieties of American English,
the past tense form 'got' has the meaning of the present. This arose
probably by dropping the helping verb 'have' from the past perfects 'have
to, has got: We've got to go, we've got a lot of problems' became 'We got to
go, we got a lot of problems.'
In the last paragraph, however, 'past perfects' seems to be a mistake. From the
context, I think it should be 'present perfects.'