That statement is correct! A sentence is indeed a group of words that expresses a complete thought, idea, or concept. It typically contains a subject and a predicate. Additionally, it is common practice for sentences to begin with a capital letter. This helps indicate the start of a new sentence and aids in clarity and readability. By starting a sentence with a capital letter, we can easily distinguish it from other parts of the text. So, remember to always begin your sentences with a capital letter to follow proper grammar rules.