In the following sentence, the part in brackets is incorrect. Choose the option which correctly improves the phrase “to buying” in the sentence: “The shoes were very expensive; I could not afford (to buying) them.” If no improvement is needed, select “no improvement”.

Introduction / Context:
This grammar question checks correct verb patterns in English after the verb “afford”. Many competitive exams test whether candidates know which forms of verbs (infinitive or gerund) follow particular verbs like “want”, “decide”, “afford”, or “enjoy”. Using the wrong pattern makes a sentence sound unnatural or incorrect to native and proficient speakers. Here, we must correct the phrase “to buying”.

Given Data / Assumptions:
The sentence is: “The shoes were very expensive; I could not afford (to buying) them.”
We are given four options: “buying”, “to buy”, “bought”, and “no improvement”. We assume standard modern British or international English usage. The subject “I” and the modal verb “could not” are correctly formed; only the bracketed verb phrase is in doubt.

Concept / Approach:
Certain verbs in English are followed by the infinitive form “to + base verb”, and others are followed by the gerund “verb + ing”. The verb “afford” is always followed by the infinitive, not by a gerund. Correct examples include “I cannot afford to go”, “She cannot afford to lose her job”, and “They could not afford to miss the train”. Therefore “to buying” is wrong because it mixes the infinitive marker “to” with a gerund form “buying”. We need “to buy”.

Step-by-Step Solution:
Step 1: Identify the main verb that controls the pattern. Here, it is “afford”. Step 2: Recall that “afford” usually takes the structure “afford to do something”. For example, “I cannot afford to spend so much.” Step 3: Compare each option. “Buying” alone would give “afford buying”, which is not standard usage. Step 4: “To buy” fits the pattern “afford to + base verb”, giving “could not afford to buy them”, which is correct. Step 5: “Bought” is a past tense form and would not follow directly after “afford” in this construction. Step 6: Since “to buying” is definitely wrong, the option “no improvement” cannot be selected.

Verification / Alternative check:
Search your memory for common phrases: people say “We cannot afford to make mistakes”, “He cannot afford to waste time”, and “They can afford to pay”. None of these uses “to making”, “to wasting”, or “to paying”. This pattern confirms that the correct form here is “to buy”. Also, most grammar guides classify “afford” among verbs that must be followed by the infinitive, similar to “decide to do”, “hope to do”, “plan to do”.

Why Other Options Are Wrong:
“Buying” would result in “afford buying them”, which sounds unnatural and is not the standard verb pattern.
“Bought” is a past tense form and does not fit the structure “afford bought them”. This is grammatically incorrect.
“No improvement” would keep “to buying”, which incorrectly mixes the infinitive marker and the gerund, so it is not acceptable.
Only “to buy” produces a correct and natural sentence.

Common Pitfalls:
Students often confuse which verbs take gerunds and which take infinitives. Verbs like “enjoy”, “avoid”, and “consider” take gerunds, while “want”, “hope”, “plan”, and “afford” take infinitives. Another common mistake is assuming that any form with “to” must be correct; however, “to” must be followed by the bare form of the verb, not by “verb plus ing”. Careful memorization of common verb patterns is important for accuracy in exams.

Final Answer:
The correct improvement is to buy, giving the sentence “The shoes were very expensive; I could not afford to buy them.”