Infinitives in English Grammar

(1) and (2) are incorrect because in the case of split infinitive, the word 'to' is placed between an adverb or adverb phrase and the verb. Option (4) is not applicable because (3) is correct.

(1), (2) and (3) are incorrect because in order to express the meaning more clearly, infinitive 'to' is used before the adverb that is qualifying to a verb.

(1), (3) and (4) are incorrect because the adverb ‘too’ is always followed by an infinitive preceded by ‘to’.

(1), (2) and (4) are incorrect because the verb 'make' or any of its forms do not take an infinitive preceded by 'to'.

(1) and (3) are incorrect because the infinitive coming after the verb 'behold' is never preceded by 'to'.
(4) is not applicable because (2) is correct.

(1) is incorrect because after 'had better', the infinitive is used without 'to'. (3) and (4) are also incorrect because the prepositions used here are in no way leading to an infinitive.

(1) and (3) are incorrect because it is the case of split infinitive. Adverb 'too' is always followed by an infinitive preceded by 'to'. (4) is not applicable because (2) is correct.

(2), (3) and (4) are incorrect because none of them has been constructed by using an infinitive.

(1), (2) and (4) are incorrect because the given question requires that an infinitive is to be used to join the given two sentences where it does not make use of any infinitive.

(2) and (3) are incorrect because the given sentence shows neither manner nor condition whereas the given sentence shows the purpose of going.
(4) is incorrect because (1) is correct.

(2), (3) and (4) are incorrect because when the perfect infinitive is used after the words such as could, should, might, ought, would etc, it expresses that the action pointed out by it did not actually happen whereas none of the (2), (3) and (4) satisfies this condition.

(2) is incorrect because the perfect infinitive is used when the verb expresses that the fact pointed out had happened before that represented “finite” in the verb whereas the given sentence has present infinitive, which can be used with any finite verb.
(3) is incorrect because (1) is correct and (2) is incorrect.
(4) is not applicable because (1) is correct.

(2) is incorrect because it is a perfect infinitive whereas the given question requires the answer to the present infinitive, which is formed by using to + I form of a verb.
(3) and (4) are incorrect because both of them are not infinitives in any form rather both of them represent the use of certain prepositions whereas an infinitive is formed only by the use of 'to' or sometimes without 'to'.

(1) is incorrect because an infinitive is not limited by a number.
(2) is incorrect because an infinitive is not limited by a person.
(3) is incorrect because an infinitive is not limited by a number or a person.
(4) is the correct answer as an infinitive is not limited either by a number or a person.

(1) is incorrect because an object follows the verb whereas in the given sentence, the words 'to complain' precede the verb.
(3) is incorrect because a complement follows the verb whereas in the given sentence, the words 'to complain' precede the verb.
(4) is incorrect because a preposition usually comes after the verb or it precedes a noun or an object whereas in the given sentence, the words “to complain” precede the verb.

(1), (2) and (4) are incorrect because “to” is not used to make a verb look like an infinitive in the sentence.

(2) is incorrect because it does not make use of an infinitive whereas the given question requires the use of an infinitive.   
(3) is incorrect because it has changed the meaning of the sentence, which now means that the child is so young that he can understand whereas the given question says that the child is so young that he    cannot understand. (4) is not applicable because (1) is correct.

(2), (3) and (4) are incorrect because in an affirmative sentence if dare is used, then it takes 'to' to form an infinitive of the verb whereas none of the (2), (3) and (4) fulfils this condition.

(1) and (3) are incorrect because the given two sentences are to be combined by making use of an infinitive whereas none of them has been combined by making use of 'to'.
(4) is incorrect because (2) is correct.    Answer: (2)

(1) is incorrect because an object comes after the verb whereas in the given sentence, the infinitive appears before the verb.
(3) is not applicable because (2) is correct and (1) is incorrect.
(4) is not applicable because (2) is correct and (1) is incorrect. Answer: (2)

We form the perfect infinitive with 'to + have + the -ed form of a verb'. We use the perfect infinitive after verbs such as claim, expect, hate, hope, like, love, prefer, pretend.
(3) is not applicable because (1) is correct and (2) is incorrect.
(4) is not applicable because (1) is correct and (2) is incorrect and (3) is also incorrect. Answer: (1) 

(1) and (2) are incorrect because in the case of split infinitive, the word 'to' is placed between an adverb or adverb phrase and the verb. (4) is not applicable because (3) is correct

(1), (3) and (4) are incorrect because the infinitive “to”, however in exceptional cases, in order to express the meaning more clearly, may be used before the adverb that is qualifying a verb.

(1), (2) and (4) are incorrect because the given question requires an infinitive to be used to combine the given pair of sentences whereas none of the (1), (2) and (4) is making use of 'to' to make the sentence look like having been used as an infinitive.

(1) and (2) are correct because like a noun 'To speak' is the subject of the verb “is” but like a verb it also takes an object (the truth). That is why (3) is correct.
(4) is not applicable because (3) is correct.