You should not say: I'm giving you leadway.

You should say: I'm giving you leeway.

For example: I'm giving you leeway to do what you want with the remaining fruit snacks in the pantry.

NBC

You should not say: for all intensive purposes.

You should say: for all intents and purposes.

For example: This mandate, for all intents and purposes, is no longer effective.

Disney / Via giphy.com

You should say: beck and call.

For example: He/she/they waited on the tyrant's beck and call.

You should say: tongue-in-cheek.

For example: Although the kids pretend that their French fries are cigarettes, it's really just a tongue-in-cheek joke among them.