Why use "me/nos" and not "Yo/nosotros"?
La mujer está trabajando con una computadora. Nos estamos subiendo al bote. Me estoy subiendo al taxi. Ella se está subiendo al automóvil.
Hello.Why are in some sentences used "me,nos.."etc, why can't there be just Yo/Nosotros? + In one sentence is even "Se" , why? I haven't found any grammar rule or something,which explains why,how and when I have to use them that way. (usually "me,te.."etc means to/for someone and se is with reflexive verbs,but in this case??)
6 Answers
La mujer está trabajando con una computadora. Nos estamos subiendo al bote. Me estoy subiendo al taxi. Ella se está subiendo al automóvil.
Hello.Why are in some sentences used "me,nos.."etc, why can't there be just Yo/Nosotros? + In one sentence is even "Se" , why? I haven't found any grammar rule or something,which explains why,how and when I have to use them that way. (usually "me,te.."etc means to/for someone and se is with reflexive verbs,but in this case??)
Yo/Nosotros, etc are subjects. They are the equivalent of "I/We/He/You" in English.
You go to the store. Tú vas a la tienda.
We shop. Nosotros vamos de compras.
However, in Spanish, you don´t always have to state the subject, since the conjugated verb indicates who the subject is. The above sentences can also be written:
Vas a la tienda.
Vamos de compras.
The verb tense of "ir" in both of those sentences tells us who the subjects are: you and we, respectively.
In the example you provided, the me/nos are from an reflexive verb. They are NOT subjects of the sentence. They are not the English equivalent of "I/We". They are more like "myself" and "ourselves" in English.
The verb in the sentences you provided is "subirse" which is "to board (oneself) on_(transportation)__" Therefore, if you are saying "You are boarding the bus" you would say "Tú te subes al autobús. (You are boarding yourself on the bus). But, as I said above, the "Tú" isn´t necessary since it is already indicated by the conjugation of the verb. Therefore, "Te subes al autobús" is also grammatically correct.
In Spanish, there are many pronomial verbs (which include reflexive verbs), and that is how they are conjugated.
The verb is subirse. It is reflexive. That is why you see "nos/me/se." And "se" is in there because the subject is "ella" which is third person singular. The conjugation for subirse in 3rd person singular is "se sube."
this is the language
Consult the phrasebook.
When you learned English, you accepted it at face value. Spanish has been around for a long time, and you just have to say, "That's the way it is!" just like you did with English.
Think about some of the English rules that make no sense. Now imagine having to learn them as a non native speaker.
Than you very much Missy8888!! It makes sense now 
Missy8888 I have to say that your explanation was very well conveyed! Thanks You!!
