I have many doubts about this cases (all of them were extracted from books, web pages and so on):
3 steps [color=red]to losing weight
The key [color=red]to understanding Islam
The secret [color=red]to making money online
The Secret [color=red]to Success (why there’s no “ing” like in the previous sentence)
3 steps [color=red]to lose weight
The requirements [color=red]to gain entrance . . .
I do not know why it is followed the termination “ing” after “to” when it is used the article “the” at the beggining, but in other cases not :shock: even with the same noun after “the” such as “secret” (cases 3 and 4)
Help me out with this too please!
6. We’re going to look at a number of approaches [color=red]to describing the diferrences . . .
7. From playing with sibblings [color=red]to negotiating allowances
This is a complicated subject. All the -ing forms in your examples are gerunds. There are three general observations I can make.
A gerund is a sort of noun; a verb that can have a direct object or the object of a preposition can usually also have a gerund instead of a noun.
Some verbs regularly go with gerunds, others with infinitives (and some can go with either): there is no real rule for this; you’ll have to learn which goes with what by practice, or from a dictionary.
The mistake of using the infinitive where only the gerund is right is often made, but the reverse mistake is not so frequent; when in doubt, I’d go for a gerund.
The sentences you gave are special, since their verbs all have to + gerund. This “to” is here not the infinitive particle, but a regular preposition. In other words: the gerund could in each case be replaced with a noun, as in “three steps to weight loss” or “the key to knowledge of Islam”; the gerund just behaves like any other noun.
(why there’s no “ing” like in the previous sentence)
(why there’s no “ing” like in the previous sentence)