Hi Helena, I hope this helps. I correct it as I understand it, but without asking some questions, sometimes we have different perspectives than the student, so the language can be different.

exercise 2

Because you said PROBABLY in the if sentence, I would use the 1st conditional.

exercise 2

Great job! A few notes:

- When using 'for', we need to use nouns afterwards (or verbs in 'ing' form), so "one of the most important things for..." health (the noun, not 'healthy' the adjective)

- We must say a 'successful' life, because we're describing what type of life we have. This is again a difference between an adjective and a noun - perhaps this is something you could review? It can be tricky!

- With try, you can either use the gerund ('ing' form) of the verb, or you must use 'to'. In other words: You should try going to bed OR You should try to go to bed.

- I would reconsider the phrase "People who never say no": Generally, we try to avoid double negatives. Instead, try "People who always say yes". 

- We use 'whether' instead of 'if' towards the end there because there are two choices. Either it is necessary, or it is not necessary. We usually ask these questions in the positive: "Do you think it is necessary?" "Is he good to you?" "Do you like your teacher?" etc. even if our opinion is negative, we most often phrase it positively.

- "I'm not saying" is the most common way of phrasing what you're trying to say at the end there.

For a more natural sounding English, I would rephrase as:

'Sleeping is one of the most important things for health and success in life. If you sleep irregularly, you probably don't have enough time for tasks during the day. Therefore you should try to go to bed and wake up at the same time every day and you will soon see the difference .