I like Sunday mornings because my family memburers sleep lat the time becausee so I am able to concentrate on Llearning English terms by heart.

'sleep late' means they 'have a lie in', and don't get up until later than they usually do on other days.

and, I think times flyies when I spentit is precious the time.

There is an expression: 'Time flies when you're having fun'. Time flies when you're focussed on something you're really enjoying and you don't notice time passing.

My foavourite time.

The only error here is that favourite is spelled incorrectly as "fovourite".

I like Sunday morning because my family membures ers are asleep at theat time b. Because I am able toof this, I can concentrate on Llearning English terms by heart.,

"Members" was spelt incorrectly. The first sentence was running on for too long so it could be shortened and made into two separate ones. "Because I am able to concentrate..." indicates that the family members are asleep because you are able to concentrate. Instead, separating the sentences into two and beginning the second one with, "Because of this," tells the reader that because of the previous point (the first sentence), you can concentrate on learning. "Am able to" could just be shortened to "can" in the sentence but this is down to preference. I ended the second sentence with a comma because it could be joined to the last sentence you originally had.

and, I think times flyies when I spentd this precious the time.

The sentence could be adjoined to the previous one. Instead of "fly" it should be "flies". The wrong tense of spend was used, "spent" would indicate what you did in the past, but you are speaking presently about what you think happens when you use this time so it should just be "spend".