allow doing和allow to do用法区别

Answer 1

The usage difference between "allow doing" and "allow to do" is as follows:
1. When "allow" is followed by a verb as its object, it is customary to use the gerund form, not the infinitive. For example: "Allow doing something" means "Permit something to be done."
2. Although "allow" does not normally take the infinitive, it can accept the infinitive complement structure. For example: "Allow someone to do something" means "Permit someone to perform an action."
3. In active voice, if "allow" is followed by no one, it must be followed by the gerund form. If someone follows "allow," the infinitive is necessary. For example:
- "Allow someone to do something" (active voice with a direct object).
- "Allow doing something" (active voice without a direct object).
4. In passive voice, only the structure "Be allowed to do something" is correct; there is no "someone be allowed doing something" structure. For example:
- "We were allowed to discuss in class yesterday" (passive voice with the infinitive).
- "Discussing in class was allowed yesterday" (passive voice with the gerund).
5. The structure "allow to do something" is generally not used.
6. "Allow" followed by a verb typically uses the gerund form, not the infinitive.
7. "Allow" can accept the infinitive complement structure, so "allow someone to do something" is correct.
If these structures are used passively, they become:
- "Something is allowed to be done" (to be done is the main complement).
- "Someone is allowed to do something" (to do something is the main complement).