In grammar, conditional sentences are sentences
discussing the implications of factual or hypothetical situations and their consequences. Language use different conditional constructions and verb forms (such as the conditional mood) to form the kinds of sentences.
Full conditional sentence contains two clauses: the condition or protasis, and the consequences or take you out.
If rainy] conditions [, (then) picnic will be canceled] consequences [.
Syntactic, this condition subordinate clause, and consequently is the main clause. However, the nature of the whole sentence is primarily determined by the nature of the protasis (condition) (tense and degrees factualness).
Conditional sentences in English
Conditional sentences in English can be divided into two broad classes factual / predictive and hypothetical (counterfactual), depending on the form of a verb in the condition (protasis). The term “factual” and “counterfactual” broadly in accordance with linguistic modality called realists and irrealis.
Factual / predictive condition
In construction, the clause expressing the condition that the truth condition has not been verified. Verb in the clause condition in the past tense (with the interpretation of the past) or in the present tense (with the interpretation of present or future tense). Clause may result in the past, present, or future. Generally, a conditional sentence of this group are in two groups, the “zero conditional” and, conditions or indications of potential is often called “first conditional” or “conditional one.” This class includes a universal statement (the second clause in the present, or two clauses in the past) and predictions.
The “zero” is formed with a second conditional
clause in the present tense. Construction is similar across many languages. It is used to express a certainty, a universal statement, a law of science, etc.:
If you heat water to 100 degrees celsius, it boils.
If you do not eat for a long time, you changed from hungry.
If the sea is stormy, the waves are high.
This is different from true since the introduction of the conditional “if” can be replaced with “when” or “when” (eg, “When you heat water …”), that can not be done for true conditionals.
The conditional or indicative potential, often referred to as the “first” conditional “or” conditional one, used more generally to express a hypothetical condition that potentially true, but it has not been verified. Conditional clauses in the present tense or the past and refers to the situation or event in the past. The results can be in the past, present, or future. Some examples of past conditions of the clause:
That If She took flight yesterday, She arrived at 10pm.
That If She took flight yesterday, She is somewhere in town today.
That If She took flight yesterday, Tomorrow We’ll see her.
A condition clause (protasis) in the present tense refers to events in the future, a current events that may be true or untrue, or an event which could be verified in the future. The results can be in the past, present, or future:
If it’s raining here now, then it was raining on the West Coast this morning.
If it’s raining now, then your laundry is getting wet.
If it’s raining now, There Will Be mushrooms to pick next week.
If it Rains this afternoon, then yesterday’s weather forecast was wrong.
If it Rains this afternoon, your garden party is Doomed.
If it Rains this afternoon, everybody will of stay home.
If I Become President, I’ll lower taxes.
Some of the auxiliaries (mainly be, maybe, maybe, and work) are usually not used in the condition clause (protasis) in English:
* If it will of rain this afternoon, …
* If it May have rained yesterday, …
There are exceptions, however, to be used exactly as in the first instance, namely when the action takes place if the clause after the main clause:
(The weather forecast says it’s going to rain.) Well, if it will from rain, We must take Umbrellas.
If aspirins will of cure it, I’ll [I Will] take a couple tonight instead of this horrible medicine. 
Other situations where it will be used in the if clause including when not used as auxiliary verbs, in other words when being used modally to express willingness, persistence, or willingness: