make sure that…
fixed phr..fixed phr.. To check something to be certain it is true, or to take action so you can be certain of a result.
fixed phr.. A verb phrase introducing a `that`-clause, expressing the act of taking steps to guarantee an outcome or to verify a state of affairs.
Make sure that the door is locked.
Before you leave, please make sure that all the lights are turned off.
The project manager must make sure that every stakeholder is fully briefed on the revised timeline to prevent any future misunderstandings.
This phrase is followed by a clause, often introduced by 'that', which can be omitted in informal speech.
Contrast with 'ensure' (more formal) and 'check' (which focuses only on verification, not on causing the outcome).
Please make sure that to close the window.Please make sure that you close the window.The phrase 'make sure that' must be followed by a clause with its own subject and verb, not an infinitive.