Briefly, verbals act as nouns, adjectives, and adverbs in sentences.
The participial phrase
A participial phrase begins with a past or present participle and is followed by its objects and modifiers. Like participles alone, participial phrases are used as adjectives.
In the preceding sentence, the present participle sniffing introduces the participial phrase, which includes the participle's object (air) and its modifiers (the, fresh). This participial phrase acts as an adjective modifying the subject of the sentence (Jim).
Here, the past participle trapped introduces the participial phrase trapped by the enemy. The entire phrase acts as an adjective modifying the subject of the sentence (soldiers). Notice the phrase-within-a-phrase here. By the enemy is a prepositional phrase modifying the participle trapped. Remember that phrases can act as modifiers in other phrases.
The gerund phrase
At first, a gerund phrase may look like a participial phrase because gerund phrases begin with the - ing form of a verb (riding, seeing, talking, etc.) and have objects and modifiers. But a gerund phrase always acts as a noun in a sentence, not as an adjective. Like other nouns, a gerund phrase can serve as the subject of a sentence, the object of a verb or preposition, or the complement of a linking verb.
In the following example, the gerund phrase Riding the black stallion acts as a noun and is the subject of the verb terrified.
In the next sentence, the gerund phrase seeing the suspect is the direct object of the verb reported. Notice that the entire phrase, not just the word suspect, is the direct object.
Here, the gerund phrase talking often and loudly is the object of the preposition by.
In the final example, Calling Uncle Roberto is a gerund phrase acting as the subject of the sentence. Asking for trouble is a gerund phrase acting as a complement of the linking verb is.
The infinitive phrase
An infinitive phrase contains an infinitive (for example, to sleep, to have slept, to consider, to throw) and its objects and modifiers. Infinitive phrases usually function as nouns, though they can be used as adjectives and adverbs.
In this sentence , To sleep all night is an infinitive phrase acting as a noun. It is the subject of this sentence.
Here, To take an unpopular stand is an infinitive phrase acting as a noun. It is the direct object of the predicate didn't want.
Next, the infinitive phrase to spend foolishly acts as an adjective modifying the noun money.
In the following sentence, the infinitive phrase to clear her mind acts as an adverb modifying drove. It answers the question “Why did she drive?”
Split infinitives
Breaking up an infinitive with one or more adverbs is called splitting an infinitive. Splitting an infinitive isn't considered the grammatical sin it used to be, but most careful writers still don't split infinitives unless they have a reason to do so.
Sometimes, however, not splitting an infinitive is almost impossible.
Other times, not splitting an infinitive causes ambiguity or sounds unnatural. In these cases, don't worry about breaking the old rule; clarity and smoothness take precedence over unsplit infinitives.
In this sentence, does further modify Russian efforts or discuss?
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We wanted to discuss further Russian efforts to modernize.
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Splitting the infinitive makes the sentence clearer.
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better We wanted to further discuss Russian efforts to modernize.
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Splitting the infinitive in the following sentence makes it less stilted, more natural.
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He planned to take quickly the children to another room.
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better He planned to quickly take the children to another room.
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