Culture is a way of perspective and identity, and people speaking the same language immediately bond and form a connection.
If an English speaking person learns Spanish, the underlying culture that emphasises ‘passion’ or ‘enjoying the experience’ is a more important cultural value in the countries who are natively Spanish.
The culture of a certain place may include cuisine, history, music and notable personalities, but language becomes the salt without which the culture is tasteless.
The local language is the preferred route to understand the culture due to 2 reasons:
Most people don’t speak English very well, due to their learning it as a second or third language. These people do not represent the real sampling of the country's population, just being the better-educated cosmopolitans who speak a global language.
Most translations are poor substitutes for the real cultural essence, and a person needs to learn the original language to fully understand the context and culture.
There are two ways you can write down your speech:
How you want to say it;
As an outline or a skeleton.
When you've written it down it's going to take more than several times to figure out what you're trying to say and this is the sculpting process where you edit, add, or delete parts of your speech to make it sound better.