Well, 'Like' (Preposition) is followed by a noun/ pronoun. While, 'As' (Conjunction: connecting word like And, Or, But etc.) is followed by a verb. For example, 1) LIKE a) She acted just like JESSY (noun). b) You look like HIM (pronoun). 2) AS: a) Ram acted just as I would EXPECT (verb) my brother to behave. b) You don't talk as I EXPECT from a friend to talk. You see, sentences made using 'As' are more complex, so people tend to use 'Like' more than 'As'.

Don't worry, you haven't misunderstood them. You know what they mean, it's simply that there isn't a one-to-one relationship between these words and their equivalent in other languages. The problems come when you try to translate word for word from Spanish. These are some examples of the main areas of confusion between 'as' and 'like': 1. As' means in a particular role, capacity and function, whereas 'like' means similar to. Compare these two sentences: A. He worked as a waiter. B. He worked like a slave. Clearly, in A, the man was actually a waiter at the time - that was his job/ role. In B, be wasn't literally a slave. If you work 'like' a slave, it means 'similar to' ie he worked extremely hard. or A. John swam like a fish. B. John went to Colombia as a tourist. Obviously, John wasn't really a fish - this is just an expression to say that he swam well. But in B, John really was a tourist. 2. When you are comparing two things using adjectives, you always use 'as' John isn't as old as his sister. This car is as expensive as the other one. You never use 'like' to compare in this way. I hope this helps.

You would usually use as in a sentences such as these: This table is as big as the other one. This man is not as tall as the other man. You can use like to compare how different things look: He looks like his father. This painting looks nothing like the other one.