Differences between "AS" and "LIKE"

Like and as are often confused in English. They can both be used to talk about how things are similar.

Like is followed by a noun or pronoun.

I'm like my sister.

Like my sister, I have brown eyes.

As is followed by a subject and verb.

She's a good student, as her brother was before her.

However, in spoken English, like is often used instead of as.

She's a good student, like her brother was before her.

As is used with a preposition, such as, "As in the 1960's, the population explosion will cause some problems".

We can use as in certain expressions, such as "as you know", "as you requested", "as we agreed".

We also use as......as to give comparisions.

He is as clever as his sister.

Thanks, Marta, for a good explanation for the use of LIKE and AS. Thanks a lot! 

Martha, you're really good! Finalmente I understand...Grazie! 

I'm Viola and I'm "new" here!

Thanks for de explanation, I now sure tath them can be used when you want, the only thing change is the form of the sentence must be done.

Now knowing that it will be easier ;-)