Beijing is warm. Is this sentence grammatically correct?

1. Question answer: From the formal point of view, this sentence seems to be the correct sentence with complete components in the main family table. But English can't express it like this. Traditionally, English uses the personal pronoun it to refer to the weather and puts the adverbial of place at the end of the sentence. So the original sentence must be revised to: It's warm in Beijing.

2. Language knowledge: In English, the third person nominative personal pronoun it is short and pithy, which plays a very positive grammatical role. It can be used (1) to replace a thing mentioned just now, (2) to indicate a person or a thing, (3) to indicate time, weather and distance, (4) to even change the structure of a sentence and emphasize a certain component of the sentence, and (5) to replace the subjects indicated by infinitives, gerund phrases or clauses, so that these subjects can be placed at the back of the sentence. In the fourth usage, it can be said that it has no special meaning, but it is used to help change the structure of the sentence and make a certain component of the sentence get special emphasis. This kind of sentence is what we call a stressed sentence. The general structure of stressed sentences is: it+be+ emphasis part +that (or who or which)+ other parts of the sentence. In the fifth usage, it has no specific meaning, but is only used to help the sentence adjust its structure. The real subject of a sentence is the back of the sentence, and only if it remains as a formal subject can the sentence structure be balanced. Here is an example.

3. Give examples:

What is this? This is a harvester. What is this? This is a harvester.

It's the wind shaking the window. It is the window that the wind blows.

It was late autumn. It was late autumn.

It was Tom who met your sister in the zoo yesterday. The man who met your sister in the zoo yesterday was Tom.

When is it convenient for me to call again? When is it convenient for me to come again?