Ambiguity emerges when the reference to a word or a sentence expresses more than one meaning. There are two types of ambiguity, the most widely discussed type is the grammatical or structural ambiguity, and the second one is the lexical ambiguity (Crystal, 2008: 22).
Structural ambiguity is a term used in linguistics to refer to a construction with more than one grammatical interpretation in terms of constituent analysis; it is also called grammatical ambiguity (Crystal, 2008: 458). In other words, it is the presence of two or more possible meanings within a single sentence or sequence of words, as opposed to lexical ambiguity, which is the presence of two or more possible meanings within a single word. The intended meaning of a syntactically ambiguous phrase can generally although not always be determined by the context of its use.
This type of ambiguity results from poor word choice. One must be careful when selecting phrases that taken in a connotative rather than a denotative context, and if not, there be more than one meaning. In addition to that, if the sentences which are used are not properly constructed, the results can often be confusing for readers or listeners. Here are some examples:
The chicken is ready to eat.
This sentence either means the chicken is cooked and can be eaten now or the chicken is ready to be fed.
I saw the man with the telescope.
It is either the man was with a telescope or it is me who saw a man by using a telescope.
Small boys and girls.
Either there is only small boys, or both of them (boys and girls are small).
Enraged cow attacks man with axe.
Either it was the cow with an axe that attacks the man, or it is the man who is with an axe and the cow attacks him.
Call me a doctor, please.
It means either you can call me by my profession which is a doctor, or I’m too ill that I need a doctor.
Lexical ambiguity on the other hand, is the presence of two or more possible meanings for a single word. It’s also called semantic ambiguity or homonymy. It differs from syntactic ambiguity, which is the presence of two or more possible meanings within a sentence or sequence of words.
Lexical ambiguity is sometimes used deliberately to create puns and other types of wordplay.
She is looking for a match.
Either she is looking for a match which is something used to light fire, or a match concerning football or any other kinds of sport.
The fisherman went to the bank.
Either the bank which is financial institution, or the side of the river.
Bats are useful to make your body healthy.
Bats here either a flying creature or equipment used in sports.
My pupil is good at art.
Pupil (at school), pupil (in the eye).
Flying planes can be dangerous.
The flying planes in the sky, or it comes from the verb of flying, someone tries to fly a plane.
Sources
David, C. (2008). A dictionary of linguistics and phonetics. UK: Blackwell publication.
Eysenck, M., Keane, M. (2005). Cognitive Psychology. UK: Taylor & Francis.
George, Yule. (2010). The study of language. Cambridge: Cambridge university press.