Finding people who speak English in Argentina won't be an easy task. This is especially true if you travel to smaller, more rural areas. Though Buenos Aires is a big city with a higher chance of people understanding basic English, it would still be advisable to know some basic Spanish. Things like banking and renting an apartment will be difficult to manage with no knowledge of Spanish. The same goes for getting a job. Most companies require at least some Spanish skills (unless you are working for an international company). What are you planning on doing in Argentina? If you are planning on staying there for a while, having a good knowledge of Spanish would be advantageous. For more information on language barriers in Argentina, have a look at our guide on Culture Shock.