Topicalizationwikipedia
Topicalization is a mechanism of syntax that establishes an expression as the sentence or clause topic; in English, by having it appear at the front of the sentence or clause (as opposed to in a canonical position further to the right).
topicalizationtopicalizednon-topicalisednon-topicalized statementsfrontingtopicalizing

Discontinuity (linguistics)

discontinuitydiscontinuitieslong-distance dependencies
Topicalization often results in a discontinuity and is thus one of a number of established discontinuity types (the other three being wh-fronting, scrambling, and extraposition).
There are various types of discontinuities, the most prominent and widely studied of these being topicalization, wh-fronting, scrambling, and extraposition.

Scrambling (linguistics)

scramblingunbounded scramblingword scrambling
Topicalization often results in a discontinuity and is thus one of a number of established discontinuity types (the other three being wh-fronting, scrambling, and extraposition).
Scrambling discontinuities are distinct from topicalization, wh-fronting, and extraposition discontinuities.

Wh-movement

wh-movementwh''-frontingwh-fronting
Topicalization often results in a discontinuity and is thus one of a number of established discontinuity types (the other three being wh-fronting, scrambling, and extraposition).
Wh-movement often results in a discontinuity, and in that regard, it is one of (at least) four widely acknowledged discontinuity types, the others being topicalization, scrambling, and extraposition.

Constituent (linguistics)

constituentconstituentssyntactic constituents
Topicalization is also used as a constituency test; an expression that can be topicalized is deemed a constituent.
15 of the most commonly used tests are listed next: 1) coordination (conjunction), 2) pro-form substitution (replacement), 3) topicalization (fronting), 4) do-so-substitution, 5) one-substitution, 6) answer ellipsis (question test), 7) clefting, 8) VP-ellipsis, 9) pseudoclefting, 10) passivization, 11) omission (deletion), 12) intrusion, 13) wh-fronting, 14) general substitution, 15) right node raising (RNR).

Extraposition

extraposition
Topicalization often results in a discontinuity and is thus one of a number of established discontinuity types (the other three being wh-fronting, scrambling, and extraposition).
This aspect of extraposition is unlike topicalization and wh-fronting, two other mechanisms that often generate discontinuities.

Topic and comment

topictopic–commenttheme
Topicalization is a mechanism of syntax that establishes an expression as the sentence or clause topic; in English, by having it appear at the front of the sentence or clause (as opposed to in a canonical position further to the right).

Syntactic movement

movementtracesyntactic movement
These more layered structures are likely to address topicalization in terms of movement or copying, as illustrated with the following two trees:
Movement is the traditional "transformational" means of overcoming the discontinuities associated with wh-fronting, topicalization, extraposition, scrambling, inversion, and shifting, e.g.

Syntax

syntaxsyntacticsyntactical
Topicalization is a mechanism of syntax that establishes an expression as the sentence or clause topic; in English, by having it appear at the front of the sentence or clause (as opposed to in a canonical position further to the right).

Ellen Prince

Prince, Ellen
She analyzed the pragmatic functions of syntactic constructions in English and Yiddish, including varieties of cleft and left-periphery constructions, such as topicalization and left-dislocation.

Catena (linguistics)

catenacatenae
The words corresponding to the nodes in red form a catena (Latin for 'chain', plural catenae).
The catena concept was introduced to linguistics by William O'Grady in 1998 and has been seized upon by other linguists and applied to the syntax of idiosyncratic meaning of all sorts, such as ellipsis mechanisms (e.g. gapping, stripping, VP-ellipsis, pseudogapping, sluicing, answer ellipsis, comparative deletion), predicate-argument structures, and discontinuities (topicalization, wh-fronting, scrambling, extraposition, etc.).

Dependency grammar

dependency grammardependentdependency
If, in contrast, less layered structures are assumed as for example in dependency grammar, then many instances of topicalization do not involve a discontinuity, but rather just inversion.
Comprehensive dependency grammar accounts of topicalization, wh-fronting, scrambling, and extraposition are mostly absent from many established dependency-based frameworks.

Ulster English

BelfastUlsterNorthern Ireland
In general, Ulster English speakers' declarative sentences (with typical grammatical structure, i.e. non-topicalized statements) end with a rise in pitch, which is often heard by speakers of non-Ulster English as a question-like intonation pattern.

Spanish object pronouns

Simple non-emphatic clitic doubling is most often found with dative clitics, although it is occasionally found with accusative clitics as well, particularly in case of topicalization.

Khmer grammar

Khmer
Topicalization is common: the topic of the sentence is often placed at the start, with the rest of the sentence a comment on that topic.

Spanish language

SpanishSpanish-languageCastilian
The language is classified as a subject–verb–object language; however, as in most Romance languages, constituent order is highly variable and governed mainly by topicalization and focus rather than by syntax.

Tîrî language

Tîrîcirmeg
As indicated in the table above, Tîrî pronouns change form depending on whether they are being used as subjective, objective or free forms, the latter encompassing a variety of other pronoun usages, such as pronouns that have been topicalized and occur sentence-initially, as seen below (Osumi, 1995, pp. 39–40).

Parasitic gap

parasitic gapparasitic gaps
Their appearance appears to be reliant on syntactic movement (e.g. wh-movement or topicalization).

Subject side parameter

SOV
SVO word order is thought to be derived from SOV word order to avoid the possible ambiguity caused by the topicalization of the objects.

Chinese grammar

ChineseChinese aspectsChinese aspect markers
In particular, a direct (or sometimes indirect) object may be moved to the start of the clause (topicalization).

Czech language

CzechcsCzech-language
In practice, however, word order is flexible and used for topicalization and focus.

Hoava language

Hoavahoa
There are some modifications to this particular pattern for focusing and topicalization purposes (Davis 2003).

Asturian language

Asturianasturian languageBable
Its word order is subject–verb–object (in declarative sentences without topicalization).

Movement paradox

movement paradox
A transformational approach to syntax will explain all sorts of discontinuities (e.g. wh-fronting, topicalization, extraposition, scrambling, inversion, shifting) in this manner in terms of movement.