There are two categories of phrases. Those start with `to` & those who start with `to be`.

when we use `to` phrase, like `to take care of`, we have to replace `to` with subject (nouns and pronouns - I, we, you, he, she, it, they, sunil, Raya, my dog etc). care is to be taken for tenses and singularity & plurality of the subject. we can make many sentences including basic 12 sentences of basic 12 tenses like..(to understand this members can translate the following in their own mother tongue).

I take care of my parents (mp)

I am taking care of  mp

I have taken care of mp

I have been taking care of mp

I took care of mp

I was taking care of  mp

I had taken care of mp

I had been taking care of mp

I will take care of mp

I will be taking are of mp

I will have taken care of mp

I will have been taking care of mp

We can make about 38 such sentences using can, could, should, must, need, want etc.

when we use `to be` phrase, we use subject in place of `to` and helping verbs like `am, is, are, was, were,  etc). Like `to be famous for`.

Sunil is famous for English. Afghanistan is famous for dates. They are famous for their skills in craft etc. However, we cannot make many sentences of `to be` phrases.

Sunil