The Spanish phrase 'demostrar una hipótesis' translates to 'demonstrate a hypothesis' in English. In scientific use, it generally refers to the process of providing empirical evidence or logical reasoning to support or reject a scientific theory or presumption. In a broader context, it can also mean to illustrate or explain a theory or assumption.

The Spanish phrase 'recoger las maletas' translates to 'collect the bags' in English. It's a common phrase used in travel contexts, often in airports or other transportation hubs where individuals need to pick up their luggage from a certain place. 'Recoger' means 'to collect' or 'to pick up', 'las' is the definite article 'the', and 'maletas' means 'bags' or 'suitcases'. Therefore, if someone says 'recoger las maletas', they're asking to collect or pick up the bags.

The word 'piso' is the Spanish translation for English word 'floor'. It is used in the same way as 'floor' is used in English: to refer to the surface of a room on which one stands. It can also denote the level of a building. For example, 'vivo en el quinto piso' means 'I live on the fifth floor'. It's important to note that 'piso' refers to the inside of a building. For outside surfaces, 'suelo' would be more appropriate to use.

The Spanish word 'simplemente' is used in the same way as 'simply' in English. It is typically used to emphasize a fact, statement, or explanation. It can be used at the start of a sentence, in the middle, or at the end, depending on the context and the emphasis intended, much like the English usage.

The Spanish phrase 'hacer calor' is frequently used in daily conversation to describe the weather. It is generally translated into English as 'to be hot'. Unlike the direct English equivalent, this phrase uses the verb 'hacer' instead of 'estar', adapting to the Spanish way of expressing weather conditions. Therefore, 'hacer calor' literally means 'it makes heat' but is understood as 'it is hot'. It is usually used when the weather is particularly warm.

The Spanish phrase 'dejar una propina' is translated to English as 'leave a tip'. It is often used in contexts such as dining out at restaurants or utilizing services where tipping is a norm. Just as in English-speaking countries, in Spanish-speaking regions tipping is a way to show gratitude for good service. Remembering nuances such as these can greatly enhance your command and understanding of the Spanish language.