Zero Conditional is used to express(a general truth или the probable future)
In the If/When-clause we usually use(Present Simple или Future Simple)
In the main clause we usually use(Present Simple или Future Simple)
In this type of conditionals, we(can или cannot) use when instead of if.
Unless means(if или if not)
When the main clause comes before the if-clause,we(use или dont use)a comma between them.
When the if-clause comes before the main clause,we(use или do not use)a comma between them.

Zero Conditional is used to express a general truth.
In the If/When-clause we usually use the Present Simple.
In the main clause we usually use the Present Simple.
In this type of conditionals, we can use when instead of if.
Unless means if not.
When the main clause comes before the if-clause, we do not use a comma between them.
When the if-clause comes before the main clause, we use a comma between them.

The Zero Conditional is used to talk about facts, general truths, or natural laws. It expresses a cause-effect relationship where the condition and the result always happen together. We use the Zero Conditional to talk about things that are always true.

For example:
- If you heat ice, it melts. (This sentence expresses a general truth that whenever you heat ice, it always melts.)

In the If/When-clause of the Zero Conditional, we use the Present Simple tense. The Present Simple tense is used to talk about things that are generally true or always true.

For example:
- If it rains, water gets wet. (This sentence expresses the fact that whenever it rains, water always gets wet.)

In the main clause of the Zero Conditional, we also use the Present Simple tense. This is because we are talking about the result or the consequence of the condition.

For example:
- If you study hard, you get good grades. (This sentence expresses the fact that whenever you study hard, you always get good grades.)

In the Zero Conditional, we can use "when" instead of "if" to talk about something that always happens.

For example:
- When you mix blue and yellow, you get green. (This sentence expresses the fact that whenever you mix blue and yellow, you always get green.)

The word "unless" is used to mean "if not". It introduces a negative condition that must be met in order for the result to happen.

For example:
- You will fail the test unless you study. (This sentence means that if you don't study, you will fail the test.)

When the main clause comes before the if-clause in the Zero Conditional, we do not use a comma between them. The two clauses are directly connected without any separation.

For example:
- Water boils if you heat it. (This sentence means that water boils when you heat it.)

However, when the if-clause comes before the main clause, we use a comma between them to separate the two clauses.

For example:
- If it rains, water gets wet. (This sentence means that if it rains, then water gets wet.)

By understanding and applying these rules, you will be able to use the Zero Conditional correctly in your writing and speaking.