A very intensive Dutch course will be the key if you want to learn Dutch fast. You might want to learn the language fast because you need it for your job or you wanna keep up with your partner. With an intensive Dutch course you will get a lot of personal attention. This will help you because you will have more chances of getting corrected when you are doing something wrong. This is nice because then you will learn from your mistakes fast and will get better faster.
An intensive Dutch course is way more personal than a normal Dutch course. Thats also why its an intensive Dutch course. They will be way stricter towards you and you will have smaller classes. You will also probably have one on one classes with your teacher. Especially when practicing speaking. With an intensive Dutch course you will learn everything about the Dutch language in a fast phase. So you will feel more comfortable speaking Dutch after every class.
Language and culture
In an intensive Dutch course you will of course mostly focus on the language. But you will also get classes in culture. This is very important because then your will start to understand the linguistics better. A language says a lot about the culture and the other way around. So have culture classes in your intensive Dutch course will help you have a better understanding of the language. This will be very helpful for when you start reading books from certain Dutch writers. It will also make you feel more connected to the language. In you intensive Dutch course you will get a little extra then in other Dutch courses. Which will maken you feel more connected and more comfortable with the language.