Welcome, Nicanora!
For only 4 weeks of study you are doing very well!
1. Yes, "la lengua" = "el idioma" = "(the) language". Each word also has some other meanings, but they do not share the other meanings. [edit]: Actually, only "lengua" has other meanings, according to at least one on-line dictionary.
2. Yes, posting messages in the forums is fine. Each forum has a name and a descriptions that identifies the types of topics and messages that are appropriate for that forum.
|