In English conditional sentences, the condition clause (protasis) is a dependent clause, most commonly introduced by the conjunction if. Other conjunctions or equivalent expressions may also be used, such as unless (meaning if...not), provided (that) , providing (that) and as long as.irst conditional or conditional I refers to a pattern used in predictive conditional sentences, i.e. those that concern consequences of a probable future event (see Types of conditional sentence).
Lesson Summary [edit]. 1  Mechanical weathering breaks existing rock into smaller pieces without changing the composition of the rock. 2  Ice wedging and abrasion are two important processes of mechanical weathering. 3  The main agents of mechanical weathering are moving water, wind, glacial ice and gravity.
Physical processes that break rock apart without changing its chemical makeup; can be caused by ice wedging, animals, and plant roots. Mechanical weathering. Mechanical weathering process that occurs when water freezes in the cracks of rocks and expands, causes the rock to break apart. Ice wedging. Occurs when chemical reactions dissolve the minerals in rocks or change them into different minerals.