The syntax of the Welsh language has much in common with the syntax of other Insular Celtic languages. It is, for example, heavily right-branching (including a verb–subject–object word order), and the verb for be (in Welsh, bod) is crucial to constructing many different types of clauses. Any verb may be inflected for three tenses (preterite, future, and unreality), and a range of additional tenses are constructed with auxiliary verbs and particles. Welsh lacks true subordinating conjunctions, and instead relies on special verb forms and preverbal particles to create subordinate clauses.
There are at least four registers or varieties of Welsh that the term Modern Welsh is used to describe. There is Biblical Welsh, which is archaic and not part of colloquial usage, although some educated Welsh speakers are familiar with it. Two more registers are Literary Welsh and Colloquial Welsh; this article primarily describes Colloquial Welsh, except where noted. Finally, there are also a number of other dialects which diverge from these three varieties of Welsh. These various dialects are understudied, with the exception of some research by Awbery (1990).