Editing Esperanto grammar (section)

===Constituent order===
[[Constituent order]] ''within'' a clause is generally free, apart from copular clauses.

The default order is [[subject–verb–object]], though any order may occur, with subject and object distinguished by case, and other constituents distinguished by prepositions:
:''la hundo ĉasis la katon'' 'the dog chased/hunted the cat'
:''la katon ĉasis la hundo''
:''ĉasis la hundo la katon''
:''ĉasis la katon la hundo''
:''la hundo la katon ĉasis''
:''la katon la hundo ĉasis''
The expectation of a topic–comment (theme–rheme) order apply here, so the context will influence word order: in ''la katon ĉasis la hundo'', the cat is the topic of the conversation, and the dog is the news; in ''la hundo la katon ĉasis'', the dog is the topic of the conversation, and it is the action of chasing that is the news; and in ''ĉasis la hundo la katon'', the action of chasing is already the topic of discussion.

Context is required to tell whether
:''la hundo ĉasis la katon en la ĝardeno''
means the dog chased a cat which was in the garden, or there, in the garden, the dog chased the cat. These may be disambiguated with
:''la hundo ĉasis la katon, kiu estis en la ĝardeno''
::'The dog chased the cat, which was in the garden'
and
:''en la ĝardeno, la hundo ĉasis la katon''
::'In the garden, the dog chased the cat'.

Of course, if it chases the cat in''to'' the garden, the case of 'garden' would change:
:''la hundo ĉasis la katon en la ĝardeno'''n''''', ''en la ĝardeno'''n''' la hundo ĉasis la katon'', etc.

Within copulative clauses, however, there are restrictions. [[Copula (linguistics)|Copulas]] are words such as ''esti'' 'be', ''iĝi'' 'become', ''resti'' 'remain', and ''ŝajni'' 'seem', for which neither noun phrase takes the accusative case. In such cases only two orders are generally found: noun-copula-predicate and, much less commonly, predicate-copula-noun.<ref name=wells>John Wells, 1978, ''Lingvistikaj aspektoj de Esperanto'', p 42 ''ff''</ref>

Generally, if a characteristic of the noun is being described, the choice between the two orders is not important:
:''sovaĝa estas la vento'' 'wild is the wind', ''la vento estas sovaĝa'' 'the wind is wild'
However, ''la vento sovaĝa estas'' is unclear, at least in writing, as it could be interpreted as 'the wild wind exists.'

When two noun phrases are linked by a copula, greater chance exists for ambiguity, at least in writing where prosody is not a cue. A demonstrative may help:
:''bruto estas tiu viro'' 'that man is a brute'.
But in some cases word order is the only clue, in which case the subject comes before the predicate:
:''glavoj iĝu plugiloj'' 'let swords become ploughs'
:''plugiloj iĝu glavoj'' 'let ploughs become swords'.