Thanks Letty, fresco and Roberta, that answered my question.
Letty wrote:Hey, Pantalones. You most assuredly are a serious student of English.
I'm a serious student because I'd like to be able to teach English and/or Spanish someday
in order to live in a foreign country for some time.
But these particular doubts come because I now use English in my job (being a programmer and sometimes needing to answer tech-support questions). I have these phrases in my mind which I sometimes use but I'm just not sure if I'm using them correctly, happens to me with Spanish sometimes too.