Language/English/Vocabulary/Allow,-permit-and-let

Allow, permit and let

Allow and Permit

These words have similar meanings and uses. Permit is more formal. Both words can be followed by object + infinitive. 

Examples:

• We do not allow/permit people to smoke in the kitchen.  

When there is no personal object, an -ing form is used after allow/permit. 

Example:

• We do not allow/permit smoking in the kitchen.  

Passive structures are common; personal subjects and gerund {-ing form) subjects are both possible.

Examples:

• People are not allowed/permitted to smoke in the kitchen.

• Smoking is not allowed/permitted in the kitchen. 
• Due to the current curfew, people are not allowed/permitted on the street after 9pm.
• Due to the current curfew, walking in the street is not allowed/permitted after 9pm.

The passive structure with "it" is only possible with permit. 

Example:

• It is not permitted to smoke in the kitchen. (but not: It is not allowed to smoke in the kitchen)  

Allow, but not permit, can be used with adverb particles. 

Example:

• She wouldn’t allow me in.
• Emily isn’t allowed out at night.  

Let

Let is the least formal of these three words, and is followed by object + infinitive without to. 

Compare:

• Please allow me to buy you a drink, (polite and formal)

• Let me buy you a drink, (friendly and informal)  

Let is not usually used in the passive. 

Example:

• I wasn’t allowed to pay for the drinks, (not I wasn't let)   

Let can be used with adverb particles; passives are possible in this case.

Example:

• She wouldn't let me in.
• I’ve been let down.