1 Many nouns can be followed by a to-infinitive clause which indicates the purpose or function of the thing referred to, e.g. a party to celebrate her 18th birthday, a device to measure energy consumption, legislation to combat age discrimination.
2 Any noun which refers to something quantifiable may be preceded by too much or enough and followed by a to-infinitive clause. The to-infinitive clause may be negative, beginning with not.
Unfortunately nobody, including Dennis, had enough money to pay for it.
He was in too much pain to speak.
I still have enough sense not to jump out of a third-floor window simply because I happen to be on the third floor.
3 A to-infinitive clause is used after any noun preceded by the and a superlative adjective or an ordinal such as first or second. The noun refers to the understood Subject of the to-infinitive clause.
It will be the largest crowd to watch a soccer college tournament live in this country.
She was the first woman to be appointed a State Governor in India.
4 Conversion note: inserted number. If the adjective is best, right, or only, the noun may refer to a person and be followed by a clause with that person as the understood Subject.
He was not the right person to lead us into the next decade.
5 Conversion note: inserted number. Alternatively, the noun may refer to a person or thing and be followed by a to-infinitive whose understood Subject is someone or something else.
Eventually she decided that teaching was the right path to take.
6 Conversion note: inserted number. Sometimes a noun is used with the but without an adjective to mean 'the right one'.
The board believes he is the man to help steer the club out of the relegation zone.
7 Any noun which refers to a person of a particular kind can be followed by a to-infinitive clause if it is used with the modal auxiliaries must and have to, or with the verb need. The to-infinitive clause in these examples means 'in order to'. The Subject of the main clause is the same as the understood Subject of the to-infinitive clause.
You don't have to be a genius to guess what happens in the movie.
You need to be a small compact person to enjoy this car.
I would have to be a saint to put up with your resentments, your foot-dragging, your evil temper.
8 The noun is followed by a to-infinitive clause which indicates what can be done to or with the thing referred by the noun, e.g. a man to watch out for, a book to read, a job to do.