Locative prepositions!

At (general locative): né
In: nlá
Around, surrounding: dvú
Outside of: fri
Over: vru
Under: jba
Behind: mlu
In front of: shve
Beside:  thmi
Left of: vli
Right of: kse
North of: nro
South of: zdu
East of: gvo
West of: tsi

These are modified by a series of infixes:

To: -in-
From: -ov-
On/touching: -ól-
Toward: -al-
From one end/side to the other (along): -um-

These are inserted just before the vowel: nliná (into), jbova (from under), vrólu (on top of), vlali (toward the left of), gvumo (along the east side of). The infix -um- has special meanings when used with nlá, dvú, and fri. nlumá indicates going through something, thus going "along the inside". frumi means basically "along the outside", like walking along the outside wall of a house, we don't care which one. dvumú means going around something full circle. Adding -n to a preposition makes it behave as a root word: vrunet (top, area above), ksenít (right, sing. adj), frinush (to be outside).

Hopefully all this works and makes sense :-P