1. Guilherme should arrive in the next three minutes.
   • Should is a helping verb. It expresses likelihood.
   • Arrive is the active (main) verb in this sentence. It is intransitive.
2. The buffet looked delicious as we walked by.
   • Looked is a linking verb; the buffet isn’t actually completing any actions.
   • Walked is an active verb. It is intransitive.
3. Harper couldn’t afford another missed assignment.
   • Couldn’t helps afford. In this sentence, it indicates how possible the verb afford is.
   • Afford is an active verb. It is transitive: its object is “another missed assignment.”
4. Pietra has an extensive rock collection. She is particularly proud of her obsidian samples.
   • Has is an active verb. It is transitive: its object is “an extensive rock collection.”
   • Is is a linking verb: She = particularly proud

Here is the passage with all the gerunds bolded:

The Australian magpie is a medium-size black and white bird native to Australia. Feeding magpies is a common practice among households around the country, and there generally is a peaceful co-existence. However, in the spring a small minority of breeding magpies (almost always males) become aggressive and swoop and attack passersby. Being unexpectedly swooped while cycling can result in loss of control of the bicycle, which may cause injury. Cyclists can deter attack by attaching a long pole with a flag to a bike. Using cable ties on helmets has become common as well, and it appears to be an effective deterrent.

1. Feeding magpies is the subject of this sentence.
2. Being unexpectedly swooped is the subject of this sentence.
3. While cycling is a prepositional phrase. Cycling is the object of this phrase.
4. By attaching a long pole with a flag to a bike is a prepositional phrase. Attaching is the object of this phrase.
5. Using cable ties on helmets is the subject of this sentence.

Here is the passage with all the participles bolded. Past particles have also been italicized.

The Australian magpie is a medium-size black and white bird native to Australia. Feeding magpies is a common practice among households around the country, and there generally is a peaceful co-existence. However, in the spring a small minority of breeding magpies (almost always males) become aggressive and swoop and attack passersby. Being unexpectedly swooped while cycling can result in loss of control of the bicycle, which may cause injury. Cyclists can deter attack by attaching a long pole with a flag to a bike. Using cable ties on helmets has become common as well, and it appears to be an effective deterrent.

1. Breeding is a present participle serving as an adjective. It modifies the noun magpies.
2. Swooped is a past participle. It works with the gerund being as a part of the subject of the sentence: Being unexpectedly swooped while cycling. “Being swooped” is a passive voice construction, so it requires the past participle.

Here is the passage with all the infinitives bolded:

The Australian magpie is a medium-size black and white bird native to Australia. Feeding magpies is a common practice among households around the country, and there generally is a peaceful co-existence. However, in the spring a small minority of breeding magpies (almost always males) become aggressive and swoop and attack passersby. Being unexpectedly swooped while cycling can result in loss of control of the bicycle, which may cause injury. Cyclists can deter attack by attaching a long pole with a flag to a bike. Using cable ties on helmets has become common as well, and it appears to be an effective deterrent.

1. Result is the bare-infinitive. It works with the verb can. Can indicates a possibility in this sentence.
2. Cause is the bare-infinitive. It works with the verb may. May indicates a possibility in this sentence.
3. Deter is the bare-infinitive. It works with the verb can. Can indicates a possibility in this sentence.
4. To be is the to-infinitive. It works with the verb appears.

1. The future continuous is either will be + present participle or is going to be + present participle:
   • Calebe will be filing a complaint against the city.
   • Calebe is going to be filing a complaint against the city.
2. The past perfect is had + past participle:
   • Cecília had sworn to never again eat another slice of carrot cake.
3. The present continuous is has been + present participle:
   • Avi has been singing with his friends at least once a week.