One subject, one verb -- simple sentence
2 or more simple sentences, put together with a semi-colon or comma or conjunction -- compound sentence
one independent clause, one or more dependent clauses -- complex sentence
2 or more independent clauses and 1 or more dependent ones -- compound-complex sentences
In vinegar, water is the solvent and acetic acid<span> is the solute. </span>Bronze<span> is a solid </span>solution<span>. Tin is the solute and copper is the solvent.</span>
Idiom is an expression particular to a region