Understanding Sentence Improvement and Verb Agreement

The question asks us to improve the bracketed part "(has happen)" in the sentence: "Yes, amazing things (has happen) with the launch of the internet." We need to find the correct verb form and tense that fits grammatically and contextually.

Analyzing the Original Sentence

The original sentence is: "Yes, amazing things (has happen) with the launch of the internet."

Let's look closely at the bracketed part "(has happen)".

• The subject of the verb is "amazing things".
• "Things" is a plural noun.
• The auxiliary verb used is "has". "Has" is used with singular subjects (he, she, it) or 'I' and 'you' in certain structures, but specifically 'has' is the singular form for third person singular (he/she/it) in the present perfect tense.
• The main verb used is "happen". This is the base form of the verb.

The combination "has happen" is grammatically incorrect for two reasons:

• Subject-Verb Agreement: The plural subject "amazing things" requires a plural verb. "Has" is a singular auxiliary verb.
• Verb Form: When using "has" or "have" as an auxiliary verb to form a perfect tense (like present perfect or past perfect), the main verb must be in its past participle form. The past participle of "happen" is "happened", not "happen".

Therefore, the phrase "(has happen)" needs improvement.

Evaluating the Improvement Options

Let's examine each option provided to see which one correctly improves the sentence.

Option 1: is happening

• This uses the present continuous tense (is/are + verb-ing).
• For the subject "amazing things" (plural), the correct auxiliary verb for present continuous would be "are", not "is".
• While amazing things might still be happening, the structure "with the launch of the internet" suggests a connection to an event that happened in the past (the launch), and the results or occurrences since that launch. The present perfect tense is typically better suited for actions that started in the past and continue to have relevance in the present, or actions completed in the past at an unspecified time with present results.
• This option is incorrect due to subject-verb agreement ("is" with a plural subject) and potentially the tense choice in this context.

Option 2: had happened

• This uses the past perfect tense (had + past participle).
• The past perfect tense is used to describe an action that was completed before another action in the past. The sentence "Yes, amazing things had happened with the launch of the internet" implies that the amazing things happened *before* the launch, which doesn't make sense. Alternatively, it could mean they happened before some other unmentioned past event related to the launch.
• While grammatically correct in terms of subject-verb agreement ("had" works with both singular and plural subjects), the past perfect tense doesn't fit the context as well as the present perfect tense, which connects past events (the launch) to present results ("amazing things" that have occurred since then).

Option 3: have happened

• This uses the present perfect tense (have/has + past participle).
• The subject is "amazing things" (plural). The correct auxiliary verb for a plural subject in the present perfect tense is "have".
• The past participle of "happen" is "happened".
• So, "amazing things have happened" correctly forms the present perfect tense and shows correct subject-verb agreement.
• The present perfect tense "have happened" fits the context well. It indicates that since the launch of the internet (a past event), amazing things have occurred, and these occurrences are relevant or connected to the present moment.
• This option is grammatically correct and makes sense in the context of the sentence.

Option 4: no improvement

• As discussed, the original "(has happen)" is grammatically incorrect due to subject-verb agreement and the incorrect verb form.
• Therefore, improvement is needed.

Conclusion

Comparing the options, "have happened" is the grammatically correct and most appropriate phrase to replace "(has happen)". It ensures correct subject-verb agreement for the plural subject "amazing things" and uses the correct verb form in the present perfect tense, which fits the context of things occurring since a past event (the internet launch).

Revision Table: Subject-Verb Agreement in Present Perfect

Additional Information on Subject-Verb Agreement and Present Perfect Tense

Understanding subject-verb agreement is fundamental in English grammar. The verb in a sentence must agree in number with its subject.

• If the subject is singular, the verb is usually singular (often ending in -s in the present tense, like "he walks").
• If the subject is plural, the verb is usually plural (usually the base form in the present tense, like "they walk").
• In perfect tenses (present perfect, past perfect), the auxiliary verb (have/has, had) changes depending on the subject's number, but the main verb remains in the past participle form.

The present perfect tense is formed using have or has followed by the past participle of the main verb. It is used to talk about:

• Actions that started in the past and continue to the present.
• Actions that happened at an unspecified time in the past, often with a connection to the present.
• Actions completed in the recent past.

In our sentence, "amazing things have happened with the launch of the internet," the present perfect tense "have happened" is used to describe events that occurred since the internet was launched, and these events have a relevance or impact extending to the present.