Present simple and perfect tense in the first conditional

Question

I just watched a video on first conditional and it says that we can we use the present simple, continuous or perfect tense in the IF clause. And it has given a few examples:

If I play football, I will be healthy.

If I am playing football, I will be healthy

If I have played football, I will be tired.

I have learned the first one in school but I have not yet encountered the second and the last one. What I don't understand is under what circumstances should we use the last two cases. The following are what I think:

For the second sentence, I am not playing football at present in reality, but I am imaging what would happen if I am playing football at this moment.

For the third sentence, I had not played football in the past in reality, but I am imagining what would have happened if I had played football in the past.

Is my understanding correct?

Here is the link which gives the above three examples. BBC learning english

Answer 1

Your question is seemed very important. I can describe it through three incidents.

For the first,
I am using “If I play football, I will be tired” instead of “ will be healthy” for the convenience of my description.

You are asked by someone (in the present) “Why don't you play football?”
You replied, "If I play football, I will be tired. I have a lot of homework."

Here notice that both are trying to indicate future.

For the last,
“If I have played football, I will be tired.”

And after, When you came home. Your little bro asked you, “Why don’t you play football? you were around the field and they wanted you.”
Then you replied, "If I have played football, I will be tired. I have a lot of homework."

For the second,
"If I am playing football, I will be healthy."

If you think like that. You were asked by someone around the playing field when you were playing “why are you playing football?”
Then you replied to him, "I like to play football very much. You know if I am playing football, I will be healthy. It has some physical benefits, such as lower the risk of diabetes and some cancers. have lower blood pressure. have stronger bones, muscles, and joints and lower the risk of osteoporosis. lower your risk of falls."

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Answer 2

You can use both present continuous and present perfect in the first conditional.

When you use present continuous in the first conditional, you are talking about a current action. (It may also refer to a future arrangement or an existing commitment to do something.)

1. If you are looking for John (present action), you will find him upstairs.

2. If you are helping me out here, I will finish the report. (existing commitment)

3. If you are staying for another night, we'll go to the cinema. (future arrangement)

So let's take a look at your example:

If I am playing football, I will be sweaty.

You are probably playing football at the moment and you are thinking about the possible outcome of the current state (in the future).

When you use present perfect in the first conditional, you are emphasizing the completed nature of an action (from the perspective of the future) and you want to say that one action depends on the completion of another action.

1. If she has moved into her new flat, I will visit her.

2. If I have finished doing my homework, I will go for a walk.

3. If I have played football, I will be tired.