The speaker discusses four key concepts in Portuguese grammar:
1. **Predicative**: a momentary characteristic of the subject or object that can be found in the predicate of a sentence. It can be indicative of the subject (describing the subject) or the object (describing the object).
2. **Vocative**: a term that evokes or calls someone or something. It is usually isolated by punctuation and cannot have another syntactic function.
3. **Post**: a term that explains or justifies a theme prior to it. It can appear punctuated or not and can be found between phrases or after a colon.
4. **Agent of the passive**: the term that acts in a passive sentence, where the subject suffers the action. This concept is part of the passive voice, which is one of the three possible voices in Portuguese grammar, along with active voice and reflexive voice.
The speaker explains these concepts through examples, highlighting the differences between them and how to identify them in sentences. The goal is to help students understand and apply these concepts in their own writing and speaking.
Here are the key facts extracted from the text:
1. The video discusses the parts of a sentence in the Portuguese language.
2. The indicative of the subject is a characteristic of the subject.
3. The indicative of the object is a characteristic of the object.
4. The vocative is a term that evokes or calls something.
5. The vocative is always isolated by punctuation.
6. The post is the term responsible for explaining or justifying a theme prior to it.
7. There are three possible voices for prayers: active voice, passive voice, and reflexive voice.
8. Active voice is when the subject does the action.
9. Passive voice is when the subject suffers the action.
10. Reflexive voice is when the subject suffers the action and does the action at the same time.
11. The agent of the passive is the term that acts in the passive sentence.
12. The exercises for the lesson will be available on Thursday.
13. The exercises can be found on the YouTube channel and Facebook fan page.
14. The lesson is part of a series of lessons on Portuguese language.