Tutor profile: Victor Adrian R.
When should I use vosotros vs ustedes?
Vosotros and ustedes are both used to refer to you (plural), also known as the 2nd person plural. However, their usage largely depends on which Spanish speaking country you find yourself in. For example, in Spain, a country where vosotros has been largely conserved, you would use vosotros to refer to a group of individuals that you are familiar with. They may be close friends or individuals that are younger than you, with whom you are comfortable to speak in a more informal manner. In contrast, ustedes is used to show to respect to the group of individuals you are speaking to. This is commonly because they are older than you. In contrast, in Latin American countries, such as Mexico, this is mostly not the case. Vosotros has been largely lost from these countries, to such an extent that many locals do not know how to conjugate verbs for the vosotros form! Ustedes is pretty much always used here, whether you are speaking formally or informally to a group of individuals and the verbs are conjugated as such. Within a Spanish learning environment, it is useful to learn both forms as you may need to use both forms at some point in your life. However, it is only once you visit a Spanish speaking country and gauge their usage of vosotros and ustedes that you really know which one is more appropriate to use. However, in general, both forms are used in Spain while ustedes is the predominant form in Latin America.
How do you know whether to use the perfect or imperfect tense?
The perfect tense (le passé composé) is a past tense used to refer to events that have happened at a specific moment in time and that are finished. In contrast, the imperfect tense (l'imparfait) is a past tense used to refer to events that were ongoing for a more extended period of time. In addition, the imperfect tense is often used in conjunction with a conditional clause as part of an if (si) construction. Here are some examples of these different tenses in use: Perfect tense (le passé composé) Yesterday I went to the cinema - Hier je suis allé au cinéma Here, we are talking about an event that happened at a specific moment in time (yesterday) and which is now over. Therefore, I use the perfect tense (je suis allé) rather than the imperfect (j'allais) Imperfect tense (l'imparfait) I was eating - Je mangeais Here, 'I was eating' refers to the fact that over an indefinite period of time, I was eating something! This is not an event that happened at a specific moment in time, therefore I use the imperfect (je mangeais) rather than the perfect (j'ai mangé) If I were rich, I would buy a plane - si j'étais riche, j'achèterais un avion Here, as part of a conditional 'si' construction, I am using the imperfect to introduce the hypothetical situation that I am rich.
What is a negative feedback system?
Negative feedback systems are a part of homeostasis. Homeostasis is all about maintaining a relatively stable, optimum level of a certain variable or thing within the body. This could be water potential, temperature, pH, hormone levels etc. But our environment is constantly changing and bodily processes are constantly occurring, meaning the level of any of these variables is prone to change from this desired stable, optimum level. Therefore, we need a system in place that will detect and counteract any change to the optimum level of a variable in order to bring it back to normal: this is a negative feedback system. Let's take negative feedback in osmoregulation (the maintenance of optimum blood water potential in the body) as an example. Mammals are constantly losing water (through metabolic reactions and sweating), meaning our blood water potential is constantly decreasing, relative to the optimum level. Therefore, in order to increase water potential back to the optimum level, we have osmoreceptors in the hypothalamus that detect the decrease in water potential. This causes an increased secretion of ADH from the posterior pituitary gland, which alters kidney function so that more water is conserved, as well as the feeling of thirst so that you drink more water. This therefore counteracts the decrease in blood water potential to bring it back up to the stable, optimum level that the body needs.
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