Understanding the infinitive form of verbs is essential for clear and effective writing in the OET Writing sub-test. English verbs typically have 3 to 5 forms. For example, verbs like "cut" have 3 forms (cut, cuts, cutting), "walk" have 4 forms (walk, walks, walked, walking), and "eat" have 5 forms (eat, eats, ate, eating, eaten). The infinitive form  for OET Writing  is the verb in its most basic state, such as "change" in "you need to change your dressing."

Infinitives are often preceded by "to," creating the "to + infinitive" structure, such as "to change," "to eat," or "to take." It’s crucial to note that incorrect forms like "to changing" or "to changed" should be avoided.

In OET Writing, the "to + infinitive" structure is particularly useful when explaining reasons for actions. Here are some examples:

"She took the pills to help her sleep at night." (correct) vs. "She took the pills to helping her sleep at night." (incorrect)"The documents are necessary to obtain a license." (correct) vs. "The documents are necessary to obtained a license." (incorrect)"The doctor will prescribe something to ease the pain." (correct) vs. "The doctor will prescribe something to easing the pain." (incorrect)

Using the "to + infinitive" structure helps convey intentions and reasons clearly. Master this structure to enhance your OET Writing skills. Happy writing!

For more info: https://edubenchmark.com/blog/use-the-infinitive-form-in-oet-writing/