Split infinitives occur when a full infinitive is used to split the word “to” from the bare infinitive. The following are examples:
to boldly go (perhaps one of the most famous split infinitives from Star Trek)
to carelessly toss
to carefully tread
You cannot end an infinitive with “s,” “es,” “ed” or “ing;” if these endings are present, the word is not an infinitive – it is another form of verb or verbal.
First and foremost, an infinitive is the form of the verb, but it is not a verb. Second, an infinitive can be a noun, an adjective or an adverb. And finally, it is always "to" plus a verb.
The infinitive is the base form of a verb with to. Usually it functions as a noun, although it can also function as an adjective or adverb.
Be careful with the present participle, the "ing" form - it looks just like the gerund, but the gerund is a noun and the participle is an adjective. Examples: "RUNNING along the river relaxed Tom." This is a gerund; it is a noun and the subject of the sentence. "RUNNING along the river, Tom felt relaxed." This is a participle; it is an adjective which modifies the subject, Tom.
Hint: Make sure the participle can modify the subject or the sentence will contain what we call a dangling participle. For instance, we cannot say "Trying to escape, the garbage can blocked his path." We can say, "Trying to escape, he found a garbage can blocking his path." Like any other adjective, the participle (present or past) must be next to the noun (subject or object) that it modifies.
"Angered by the article, Drake decided to write a letter to the editor." "Angered" is an adjective describing Drake's state of being; "decided" is a past tense verb stating the subject's (Drake's) action in the sentence.
Like the present participle, the past participle, when it appears with an auxiliary verb has its own special roles. Without an auxiliary verb, an "ed" verb form is simply either past tense (if it functions as a verb) or a verbal (it functions as a adjective). The present or past participle, when we use them as verbals, are adjectival in function; they modify things - subjects or objects.
The second type of participle, the past participle, is a little more complicated, since not all verbs form the past tense regularly. The following are all past participles:
the sunken ship,
a ruined city,
a misspelled word.
Note that only transitive verbs can use their past participles as adjectives, and that unlike other verbals, past participles do not take objects (unless they are part of a compound verb).
To make a present participle, you add "-ing" to the verb, sometimes doubling the final consonant:
"think" becomes "thinking"
"fall" becomes "falling"
"run" becomes "running"
A participle is a verbal that functions as an adjective.
When a “-ing” form of a verb is used following a preposition, it is always a gerund. A good way to remember this is that when a gerund follows a preposition, it is easily replaced with another noun. The gerund is the object of the preposition it follows. Consider the following examples: Example 6: "Karen stopped by her co-worker’s office before leaving."
Like nouns, we can use gerunds with adjectives (including articles and other determiners): "pointless QUESTIONING," "a SETTLING of debts," "the MAKING of Titanic," "his DRINKING of alcohol."
But when we use a gerund with an article, it does not usually take a direct object: "a settling of debts (not a settling debts)"
Like nouns, gerunds can be the subject, object or complement of a sentence: "SMOKING costs a lot of money." "I don't like WRITING." "My favourite occupation is READING."
But, like a verb, a gerund can also have an object itself. In this case, the whole expression [gerund + object] can be the subject, object or complement of the sentence: "SMOKING cigarettes costs a lot of money." "I don't like WRITING letters." "My favourite occupation is READING detective stories."
A gerund is a verbal ending in -ing that functions as a noun
Verbals are words that seem to carry the idea of action or being but do not function as a true verb. The are sometimes called "nonfinite" (unfinished or incomplete) verbs. Because time is involved with all verb forms, whether finite or nonfinite, however, following a logical Tense Sequence is important. Verbals are frequently accompanied by other, related words in what is called a verbal phrase.
The three verbals— gerunds, infinitives, and participles—are formed from verbs, but are never used alone as action words in sentences. Instead, verbals function as nouns, adjectives, or adverbs. These verbals are important in phrases.