To identify / Identifying

[ratóncolorao]

Hello,

Would you please help me with these two sentences?

…………………the main idea of each paragraph will help you understand the text.

a.- To identify b.- Identify c.- Identifying


……………………is the key to success


a.- To study b.- Studying




I would choose "a" in sentence one and option "b" in sentence two. Infinitive with TO for specific actions and -ing for general statements. What do you think?



Thank you for your help.

[5jj]

I'd use the gerund in both sentences. The infinitive is rarely used as a subject these days in normal speech and writing.