this
The German word 'das' is a definite article, which is used before a noun to indicate that the noun is specific or particular. It is equivalent to the English word 'the'. In German, the form of the definite article changes depending on the gender, number, and case of the noun it modifies. 'Das' is used with neuter nouns in the nominative and accusative cases.
That is a book.
In this example, 'das' is used as a definite article pointing to a specific object, in this case, a book. The phrase translates directly to 'That is a book' in English.
The weather is nice.
Here, 'das' is used in reference to the weather. In English, we use the definite article 'The' in the same context. So, 'Das Wetter ist schön' is 'The weather is nice' in English.
I like that.
In this sentence, 'das' means 'that' and is used as a demonstrative pronoun indicating something that is understood by both speakers. The sentence translates to 'I like that' in English.