Student or Learner
Could anyone explain to me the difference between "as" and "like"?
Do I say "do as I did" or "do like I did"?
1) Do it as I did it. - This is more natural sounding like this: Do it the same as I did. or: Do it the same as I did it.
2) Do it like I did. or: Do it like I did it.
It's considered informal to use "like" as a conjunction, though it used regularly in spoken language and in writing as well.
Using "as" as a conjunction is always correct.
When you have a choice between "as" and "like", just as in your example sentences, remember that using "like" will make your communication sound more informal.
If you are writing a business letter, for example, use "as". Sometimes it's better to use "as though" or "as if". It depends on the sentence.
I would read this usage note to gain a good understanding of "like" used as a conjunction.
like: Definition, Synonyms from Answers.com
USAGE NOTE Writers since Chaucer's time have used like as a conjunction, but 19th-century and 20th-century critics have been so vehement in their condemnations of this usage that a writer who uses the construction in formal style risks being accused of illiteracy or worse. Prudence requires The dogs howled aswe expected them to. Like is more acceptably used as a conjunction in informal style with verbs such as feel, look, seem, sound, and taste, as in It looks like we are in for a rough winter. But here too as if is to be preferred in formal writing. There can be no objection to the use of like as a conjunction when the following verb is not expressed, as in He took to politics like a duck to water. See Usage Notes at as1, together.