Final answer:
The sentence provided is a declarative sentence because it makes a statement and ends with a period, which is the punctuation typically used for declarative and imperative sentences.
Step-by-step explanation:
The sentence "Caramelizing onions takes lots of time and requires patience" is an example of a declarative sentence. Declarative sentences make a statement and end with a period. They are used to relay facts, provide information, or make declarations. This is in contrast to the other types of sentences: interrogative sentences, which ask a question and end with a question mark; exclamatory sentences, which express strong emotion and end with an exclamation mark; and imperative sentences, which give a command or request and typically end with a period but may also end with an exclamation mark to express urgency or strong emotion.