To express gratitude in Spanish, it's essential to understand the nuances of idiomatic expressions, which can be a significant challenge for non-native speakers. For example, 'gracias' is a common way to say 'thank you,' but its literal translation doesn't convey the same level of politeness as its idiomatic usage. Similarly, 'de nada' means 'you're welcome,' but it's often used in a more emphatic or sarcastic tone. To avoid misunderstandings, consider learning phrases like 'me alegra poder ayudarte' (I'm glad I could help you) or 'estoy contento de haberte podido ayudar' (I'm happy to have been able to help you), which convey a sense of appreciation and gratitude. Additionally, be mindful of the context in which you use these phrases, as tone and body language can greatly impact their interpretation.