The document discusses the preposition "at" in English grammar. It states that "at" indicates a place, event, or time, such as in the examples "I'll see you at the restaurant", "I'll see you at the seminar", or "I'll see you at 5:00pm". It then lists the headings "Grammar Patterns", "Collocations", "Set Phrases", "Examples", and "Exercises" to describe different uses of the preposition "at".

1. Native English Natural Grammar

2. At Preposition Indicates a place, an event. Or a time. I’ll see you at the restaurant. I’ll see you at the seminar. I’ll see you at 5:00pm. Grammar Patterns

3. At Preposition Indicates a place, an event. Or a time. I’ll see you at the restaurant. I’ll see you at the seminar. I’ll see you at 5:00pm Collocations

4. At Preposition Indicates a place, an event. Or a time. I’ll see you at the restaurant. I’ll see you at the seminar. I’ll see you at 5:00pm Set Phrases

5. At Preposition Indicates a place, an event. Or a time. I’ll see you at the restaurant. I’ll see you at the seminar. I’ll see you at 5:00pm Examples

6. At Preposition Indicates a place, an event. Or a time. I’ll see you at the restaurant. I’ll see you at the seminar. I’ll see you at 5:00pm Exercises (link to Quia)