Will people get annoyed if I don't speak Spanish?

Generally, no. As long as you are polite, attempt to learn the basics, and use gestures, locals are usually helpful and patient.

Is Google Translate accurate enough?

For basic communication, yes. Avoid using it for complex questions or sensitive topics, as the tone can be misinterpreted.

Navegar Sudamérica sin hablar español durante una mochila de larga duración

You can absolutely travel South America without Spanish by using offline translation apps, staying in social hostels, and learning 20 essential phrases. Rely on bus apps like Busbud and carry a physical notebook for written communication when technology fails.

Download offline language packs. Download Google Translate (Spanish and Portuguese packs) for offline use. Use the 'Camera' function to translate menus or bus signs instantly by pointing your phone at them.
Master the 'Survival 20'. Memorize 20 phrases: greetings, numbers 1-100, 'how much', 'where is', 'I am a vegetarian', 'help', and 'the bill please'. Knowing these by heart prevents you from constantly looking at your screen.
Use digital tools for transport. Use RedBus or Busbud to book long-distance buses. These platforms are available in English and eliminate the need to negotiate at physical ticket windows where language barriers are highest.
Leverage hostels for local info. Stay in highly-rated social hostels. Ask the staff to write down directions or specific requests in Spanish for you on a small card you can show to taxi drivers or shop owners.

Will people get annoyed if I don't speak Spanish?: Generally, no. As long as you are polite, attempt to learn the basics, and use gestures, locals are usually helpful and patient.
Is Google Translate accurate enough?: For basic communication, yes. Avoid using it for complex questions or sensitive topics, as the tone can be misinterpreted.