Ex: It is important to drink fluids.
Infinitive verbs do not have tense; they are in their base form (e.g., walked (tense), walk (infinitive). The infinitive has two forms: the base infinitive (e.g., walk) and the to-infinitive (e.g., to walk).
expletive subject (It) + adjective or noun (important, helpful, a good idea)
Ex: What should you do for a cold?
- It's important to drink fluids.
- It's important that you drink fluids.
- That you drink fluids is important.
- Drinking fluids is important.