The collective term ‘adpositions’ includes prepositions, postpositions and bare adpositions. They constitute a closed group of words. Adpositions are, in principle, indeclinable.

Some specific bare adpositions combine with some specific postpositions to create circumpositions: foar uus uur ‘right in front of us’, ätter de Skoule wai ‘to school’, tou de Skoule uut ‘out of the school’ etc.

Some adpositions also combine with R-pronouns: uus Mäme weet niks deerfon ‘our mother knows nothing of that’, uus Mäme weet deer niks fon (idem).

Prepositions and bare adpositions often share the same form, e.g. an dän Disk ‘at the table’ and ju Laampe is an ‘the light is on’, but not all of them do. The prepositions siet ‘since’ and sunner ‘without’ (for instance) do not feature as bare adpositions. The bare adposition wäch ‘away’ is not a preposition.

Verbal particles are elements like an in the separable complex verb ankume ‘to arrive’ (iek kume an ‘I arrive’). They often share the same form as bare adpositions (and, in most cases, prepositions), e.g. the bare adposition an. However, the verbal particle mee in meedwo ‘participate’ deviates formally from the adposition in deermäd ‘with that’ (and from the preposition mäd ‘with’, by the way). We can’t find examples featuring mäd as a bare adposition in a copular sentence.

Sater Frisian disposes of a set of so-called lengthened adpositions (gedehnte Adpositionen), all ending in a schwa. They occur in static contexts, most often in copular sentences, as well as in combination with R-pronouns.

These extended adpositions are not to be perceived as inflected forms synchronically.