The phrase 'if you allow' is correct and can be used in written English. You can use it to introduce a polite request. For example, "If you allow, I would like to make a suggestion."
If you allow them to, that is.
If you allow comments to continue, it becomes a tabloid.
Our bodies will recover by themselves if you allow time.
They could really change your life if you allow it.
What happens if you allow divorce, prostitution, gambling?
"If you allow it to be," he says.
"You confuse them if you allow them everywhere," she says.
If you allow the moral hazard to develop, if you allow people to think that, hey, let's make all these loans.
But if you allow for some variability from survey to survey, a distinctive pattern has emerged.
"If you allow pets, that sort of comes with it," Ms. Harvey said.
If you allow Andy Murray to do what he did it's nearly impossible to beat him.
When I feel like I can't trust my brain 100%, Ludwig really comes in handy. It makes me translate and proofread faster and my output more reliable.
Claudia Letizia
Head Translator and Proofreader @ organictranslations.eu