A very complicated sentence.

[sitifan]

So the approach to communicative language teaching that emphasizes the functions or speech acts that pieces of language perform overlaps in an important sense with the preoccupations of discourse analysis. (Discourse Analysis Language Teaching, by Michael McCarthy)

What is the main verb of the above sentence?

 

[Phaedrus]

Re: A very complicated sentnce.

overlaps

 

[sitifan]

What does the phrase "pieces of language perform" mean?

 

[jutfrank]

Re: A very complicated sentnce.

What does the phrase "pieces of language perform" mean?

It's part of the relative clause.

Pieces of language perform functions and speech acts.

 

[Phaedrus]

Re: A very complicated sentnce.

What does the phrase "pieces of language perform" mean?

"Pieces of language perform" is the subject ("pieces of language") and verb ("perform") of a relative clause ("that pieces of language perform") modifying the noun phrase "functions or speech acts." That relative clause and the noun phrase it modifies are embedded within a higher relative clause ("that emphasizes the functions or speech acts that pieces of language perform") modifying the simple (or simpler) sentence subject ("the approach to communicative language teaching").

The simple sentence subject is "approach," and the basic sentence asserts, "The approach overlaps with (a certain kind of) preoccupations." According to the complete subject phrase in its full 18-word glory, pieces of language perform functions or speech acts, and those functions or speech acts are emphasized by whatever approach to communicative language teaching the author is discussing in this passage. This approach overlaps in some important sense with the preoccupations of discourse analysis.

 

[sitifan]

So the approach to communicative language teaching that emphasizes the functions or speech acts that pieces of language perform overlaps in an important sense with the preoccupations of discourse analysts. (Discourse Analysis For Language Teachers, by Michael McCarthy)

I have corrected several typos. Thank you very much for your explanations. I have fully understood the structure of the quoted sentence.