<! ---------------------------------------A B H I E R B E G I N N T D E R I N H A L T ----------------------------------------->
21.4.2 exercise: Prepositon or adverb
The differences between abaixo, embaixo, debaixo is difficult to determine even for Portuguese native speakers, in other words the use is wavering and there is debate about the question in which context they are interchangeable and in which context they are not interchangeable. In practise the issue is simpler, because at least embaixo and debaixo are synonyms. In case that the adverb describes a mouvement, "I go down", "It rolled downwards", "hill downwards" etc. only abaixo is possible.
The following assertions are "destillated" from examples, but are not rules. It is not very difficult to find examples that don't comply with these assertions, however they describe a tendency.
abaixo (downwards / down (adverb), underneath (prononminal adverb), down (in the sens of "down with the dictatorship") is the opposite to acima (upwards, up). It indicates the direction of a mouvement, refers therefore to the verb. If it is used to describe a static position it means under and is a preposition. (In this case a de is to be added, abaixo de.) If it describes a mouvement, "I go down", it is an adverb. As an adverb only abaixo is possible. Used as a preposition it differs from embaixo / debaixo. As a proposition it describes a relationship between to objects, but not in a vertical sense. ("The town is below sea level". => "~The town is under sea level." ) Abaixo can be used as well in a metaphorical and psychical sense. ("I am down.")
embaixo (down, underneath) is the opposite of em cima (upon, on). Embaixo is not used to describe a mouvement. However if the end of the mouvement is indicated as well, Vou embaixo do chuveiro <=> I will take a shower, or if there is another pronominal adverb, Vou lá embaixo <=> I go down there, embaixo can be used as well. The difference between embaixo de and abaixo de is that embaixo describes an inferior relationship in space in vertical sense. (The cat is under the bed.) Embaixo can be as well a predicative noun, but in this case it is more a pronominal adverb: Eles estão embaixo <=> They are underneath. This sentence makes only sense, if we know under what they are, underneath refers to something. Embaixo alone can't be an adverb, but as a preposition it can be part of an adverbial.
debaixo can only be used with de, in other words, only as a preposition, wherin the preposition de has to comply in order and number with the following preposition. Debaixo can't be used as a predicative noun. Something like that doesn't work:: Eles estão debaixo. Debaixo can't be combined as well, A menina se escondeu aí embaixo <=> The girl hid herself down there, with another pronominal adverb. A menina se escondeu aí debaixo is wrong. Debaixo itself is not an adverb, but as a preposition it can be part of an adverbial. It can be used metaphorically. As embaixo it describes an inferior position in a vertical sense.
para baixo and abaixo: Abaixo means downwards and can be used without any object that describes the end of the mouvement: He went downwards. Para baixo is used if the beginning of the mouvement is described as well: Baixou as calças ficando nu da anca para baixo. <=> He pulled down his pants and remained naked from the hip down.
Sometimes it is important to be able to distinguish between an adverb and a preposition. (For instance is one wants to explain to someone the difference between down (preposition) and downwards (adverb)). In Portuguese it is useful to understand the difference, because the preposition has a de and the adverb not.
Decide in the following embaixo / abaixo / debaixo are used as adverbs or as prepositions.