Correct usage of the idiom "We will cross that bridge when we come to it" [closed]

Solution 1:

In "We will cross that bridge when we come to it", "come" is the simple present tense used to indicate the present in the future.

It is very common:

"I am in Paris tomorrow - I'll speak to you then"

"John leaves in an hour, don't let him forget his coat."

In "when we come to it", when = at the time that, i.e. the present tense is used to create the present at that time.

Solution 2:

The simple answer is that usually, the word "will" isn't used after "if", "when", or similar words.

Examples:

Incorrect: When the sun will rise, I will get out of bed.
Correct: When the sun rises, I will get out of bed.

Incorrect: If you will see David tomorrow, say hello to him for me.
Correct: If you see David tomorrow, say hello to him for me.

Incorrect: After we will eat dinner, we will have dessert.
Correct: After we eat dinner, we will have dessert.

Incorrect: If Sarah will cross the finish line first, she will win the race.
Correct: If Sarah crosses the finish line first, she will win the race.

Incorrect: We will cross that bridge when we will come to it.
Correct: We will cross that bridge when we come to it.