How does one know when to use a gerund or an infinitive?

Question

As a native speaker of English, the gerund version of this sentence sounds better: infinitive: > When used together in chains, > extension methods are an unprecedented > tool **to produce** extremely concise > code. gerund: > When used together in chains, > extension methods are an unprecedented > tool **for producing** extremely concise > code. But how can I explain to someone learning English how to decide in situations like these whether to use the infinitive or the gerund?

Answer 1

The second example is incorrect because you are using for producing ending -ing ending when the entire sentence usws simple present rense. The key is to see if each sentence uses the same tense thruout. And also ifnit has subject verb agreement. So the correct answer is to use infinitive here.