20.1.3. a in descriptions of spatial relationships
Very often a preposition have the unpleasant property of not being semantically very motivated. In part this is due to the fact that one can discuss about the position of an object in a three dimensional space. This complicates things. If we had a 1 to 1 relationship, we could use the same preposition in any context. However this is not the case. We have an n to n relationship. To any context we have to learn the corresponding preposition by heart.
On the beaches of the world vor instance there are very often kiosks where one can buy something to drink, icecream, hotdogs etc.. In English these kiosks are on the beach, but in Portuguese they are in the beach, na (a + em) praia. If we make camping, we put tents on open air. That's not the way Brasilian or Portuguese see it. They put their tents to the open air, ao ar livre and not em ar livre.
However, and that is strange, in other actually more complex cases the human brain makes always the same analogies. If we run against a wall or if we fight against something are two very different things. The only similarity is the fact that there is something that resists. However in all languages against is used as well in this metaphorical sense. This is even so obvious, that most people are not even aware that it could be different.
However sometimes a language make distinction that are not made in other languages. In English for instance people go to the United States. Whether they go on holidays or to settle there is irrelevant. In Portuguese people make a trip aos Estados Unidos, but if they have the intention to stay there forever or for a long time, they go para aos Estados Unidos.
This author would say that prepositions are an underestimated phenomenon in language learning. Given their sometimes weak motivation a lot of combinations, for instance which preposition has to be used in the case of prepositional objects, see 20.1.2, has to be learned. We will try to discuss the most relevant prepositions that are problematic for whatever reason. Together with this grammar we supply several audio book. The author doesn't believe really that thousands of contexts can be learned by heart, but he believes that one learns things automatically by reading and hearing. Grammar rules reduce the amount of variations, because in any context the same rules apply. One can learn them by discussing them. The less rules there are, the broader the range of variations, and concerning prepositions there are very few stable rules, the more it becomes a lexical problem. Their use is very often arbitrary.
a to indicate a direction
Amanhã vou a Lisboa.
Tomorrow I go to Lisbon.
Vou à escola todos os dias.
I go to school every day.
Gostaria de ir com você ao cinema.
I would like to go to the cinema with you.
para if one goes somewhere for a long time
Os covardes não vão para o Céu.*
The cowards won't come into heaven.
* Given that one stays in heaven for a longer time, the preposition is para, see remarks above.
In indications with left, right English distinguishes between a mouvement and a static position, although not always the same prepositions are used.
Look to the right.
Turn to the right.
Keep on the left.
If a static position is described, we use another preposition in English.
He is on the right side of the door.
On the right side of the Rhin it is as beautiful as on the left side.
This distinction is not made in Portuguese. It is always à direita / à esquerda.
Virem à esquerda, depois à direita.
First turn to the left, then to the right.
Olhem para a esquerda, depois para a direita.
First look to the right, then to the left.
O elevador fica aqui ao lado à esquerda.
The elevator is around the corner on the left. .
Duas quadras a direita tem um restaurante.
Two street blocks ahead on the right there is a restaurant.