This work is an attempt at showing the main similarities and differences of expressing condition in English and in Polish. Taking into consideration the complexity of the subject matter I decided to carry out my analysis by following some principal aspects of conditional structures, i.e. possible classification, moods, time reference, condition fulfilment, relations between the clauses, the role of context, clause order and conjunctions.

Conditionals belong to a group of adverbial clauses and generally they answer the question: “under what condition?”. This means that they define or describe the condition understood as a set of circumstances necessary or sufficient for a certain event to occur. They may, however, communicate also wishes, regrets, advice, polite requests, demands, suppression or commands. They sometimes function as conversation friendly devices (speech act conditionals). Moreover, there is a certain area where conditionals overlap with concessives and a clear borderline between these two is impossible to establish. Therefore, the term conditional clause covers a wide spectrum of possible interpretations.

Both in English and in Polish condition may be expressed by means of simple or complex sentences or sentence equivalents. To date, many classifications of conditionals have been postulated. The most popular seems to be the division into real, probable and unreal, or open and hypothetical, the latter divided into those which are contrary to expectations and those which are contrary to the fact.