Understanding Sentence Substitution in English Grammar

The question asks us to find the most appropriate option to replace the underlined segment 'certain go' in the sentence: "I'm certain go to start studying from today." This sentence contains a grammatical error that needs correction. The verb 'to be' (in this case, contracted as 'm' in 'I'm') is followed by an adjective 'certain' and then a base verb 'go'. This structure is incorrect in standard English when expressing a future intention or certainty about an action.

Analyzing the Original Sentence Error

The phrase "I'm certain go" is grammatically flawed. When using 'to be' followed by an adjective, the structure usually involves a linking verb followed by a complement (adjective or noun), or it is part of a larger construction. Here, 'certain' is an adjective, and 'go' is a verb. To express a plan or intention about the future, especially with certainty, we often use structures involving adverbs or gerunds/participles.

Evaluating the Substitution Options

Let's examine each provided option for substituting 'certain go':

1. certain going: If we substitute this, the sentence becomes "I'm certain going to start studying from today." While 'going' can follow 'I'm' (as in 'I'm going'), the adjective 'certain' placed directly before 'going' in this structure is not standard for expressing certainty about a future action using 'going to'. We might say "I am certain that I am going..." or use an adverb.
2. No substitution required: As identified earlier, the original sentence "I'm certain go..." is grammatically incorrect. Therefore, substitution is required to make the sentence correct.
3. certainly go: Substituting this gives "I'm certainly go to start studying from today." 'Certainly' is an adverb, which can modify a verb. However, the structure 'I'm + adverb + base verb' is not a correct English construction. We might say "I certainly go..." (Simple Present, for habitual action) or "I will certainly go..." (Simple Future).
4. certainly going: Substituting this gives "I'm certainly going to start studying from today." Here, 'certainly' is an adverb modifying the verb phrase 'going to start'. The structure 'Subject + be + adverb + going to + base verb' is a correct and common way to express certainty or emphasis about a future plan or intention. For example, "She's certainly going to win." or "They are certainly going to arrive on time." This structure fits perfectly with the intended meaning of the original sentence.

Identifying the Correct Substitution

Based on the analysis, the option that results in a grammatically correct and meaningful sentence is 'certainly going'. The corrected sentence, "I'm certainly going to start studying from today," correctly uses the adverb 'certainly' to modify the future construction 'going to start', expressing the speaker's strong intention or certainty about starting their studies.

Correct Sentence Construction

The most appropriate substitution is 'certainly going'. The corrected sentence is:

"I'm certainly going to start studying from today."

Revision Table: Key Concepts in Sentence Correction

Additional Information: 'Certain' and 'Certainly' Usage

Understanding when to use 'certain' (adjective) and 'certainly' (adverb) is crucial for correct sentence construction. 'Certain' describes a state of being sure or something that is guaranteed. 'Certainly' describes how an action is performed or the degree of sureness about an action or statement.

• Certain (Adjective):
  • He is certain about his decision. (Certain describes "He")
  • It is certain that they will win. (Certain is a subject complement describing "it")
• Certainly (Adverb):
  • He will certainly arrive on time. (Certainly modifies the verb "arrive")
  • That is certainly a difficult task. (Certainly modifies the adjective "difficult")
  • Certainly, I can help you. (Certainly modifies the whole sentence, expressing affirmation)

In the original sentence, we need to modify the action of 'going to start studying' with a sense of surety. An adverb is needed for this purpose, making 'certainly' the correct choice. Furthermore, when using the 'going to' future construction with 'I'm', the verb following 'going to' is the base form ('start'), while 'going' itself follows 'I'm'. Thus, 'certainly going' correctly combines the adverb and the present participle/gerund form needed here.