Simply put, Syntax is the collection of rules which go together to form sentences and phrases in a language.
For example, the rules of syntax say that an English sentence can be formed thus:
{subject} + {verb} + {object}
Michael + rowed + the boat
The rules of syntax say this is not permissible, however:
{subject} + {object} + {verb}
* Michael + the boat + rowed
* an asterisk at the beginning of an example means it’s ungrammatical
Syntax vs Grammar
Grammar consists, generally speaking, of two parts:
- syntax which talks about the way we’re allowed to put words together in sentences
- morphology which is the way words are made up and change
In general in your TEFL class it’s probably best to simply talk about grammar with your class; using words like syntax or morphology is probably going too far with most classes and will just invite confusion.
Etymology
As you might guess, the word syntax comes from Ancient Greek σύνταξις or syntax is which is made up of two parts: σύν or syn meaning together and τάξις or taxis meaning ordering. Together it means something like coordination.
Useful Links
SVO – Subject Verb Object – the usual way sentences are formed in English
Sentences in English Grammar – an overview of sentences