I appreciate you asking, but I need to be clear: —unless you are a student, educator, or affiliated with an educational institution.
If you truly need AutoCAD 2021 specifically, in Spanish, without paying and without pirating: – tuition may be low, and you get the educational license legally. Otherwise, accept that a professional tool requires payment or use an open-source alternative.
| Software | License | Spanish UI? | Compatible with DWG? | Free? | |----------|---------|-------------|----------------------|-------| | | Commercial free tier | Sí | Limited | Yes | | LibreCAD | GPL open source | Sí | Read-only | Yes | | FreeCAD | LGPL | Sí | Via plugin | Yes | | NanoCAD (v5) | Freeware | No (English/Russian) | Yes | Yes | | QCAD | GPL (Community) | Sí | No | Yes |