"Does a coalition democracy allow its citizens more or less say in government affairs than a representative democracy? To what extent?"

A coalition democracy probably allows its citizens more say than a representative democracy. A coalition usually consists of two parties with similarities as well as differences. That means that not only the opinions of the citizens who voted for the major party, but also the opinions of the citizens who voted for the party which forms a coalition with the major party, are represented in the government.

On the other hand a representative democracy also allows its citizens a lot of say in governmental affairs because the party with the most elected representatives is the ruling party. Therefore the majority of the citizens voted for the ruling party and influenced the government.

In fact, there are usually two powerful parties in a coalition democracy and therefore more opinions represented in the governmental affairs, the citizens of a coalition democracy have more influence than the citizens of a representative democracy. However, in a representative democracy the major party rules, that means that the opinion of the majority of the citizens is represented. So the difference of influence of the citizens is not that big, because in both cases the majority of the citizens is represented.