The subject of prepositions in Basic English is often asked. Here is a brief summary of what Ogden and others have said on the subject. Ogden calls his list of 21 prepositions, "directions" or "directives". These when combined with the 16 verbs make "operators". Operators can say hundreds of action words of standard English.

Basic English : International Second Language by Ogden

Learning Basic English by Richards

Basic English : A General Introduction with Rules and Grammar by Ogden

Chapter 3 Grammatical Principles The combination of the ten operators and the three operator-auxiliaries with the twenty directives immediately gives us equivalents of roughly 200 simple English verbs. Directives The root meanings of these words is made clear by the drawing.

The Basic Teacher by Lockhart

Basic English and Its Uses by Richards

Below the verbs in Column One come twenty words (about to with) whose peculiarity is that they handle positions and directions.

Techniques in Language Control by Richards and Gibson.

The twenty prepositions groups immediately below them on the list Ogden prefers to call directives because they handle positional and directional relationships. This can be demonstrated if they are first used spatially. They are separated alphabetically from the other preposition-adverbs on the list for this reason. A large number of the uses of these often trouble-making little words can become intelligible when they are introduced as pointers to positions or directions of things that can be seen or acts that an be performed. (The milk is in the bottle ; I am putting a book on the table ; He is going to the door, etc.)

The ABC of Basic English by Ogden

The Basic Words

Universal Language Dictionary Project

across (at/to the other side of) about at
after (in the future of) because of before
before (in front of) in back of in
between, among like near
for (for the purpose of) of on
for (in exchange for) other than over
from (out of) through to, at
than [pr/cj] under with