With all persons shall can be used to emphasisSpecial importance or attention given to something. E.g.: All I wanna do is have some fun.e something which the speaker feels certain to happen or wants to happen.

I shall definitely give up smoking this year!
We shall win!
"We shall overcome!"

Only if can be used to connect the main clauseA group of related words containing a subject and a verb. and the if-clause to express a more restrictive condition.

Acetaminophen is dangerous to kids only if dosage is too high.

It is possible in all types of conditionals. Note that if the sentence starts with the condition, the main clauseA clause that could be a sentence in itself. E.g.: I wouldn’t go there if I were you. ("I wouldn't go there") When I arrived he was surfing. ("he was surfing") is invertA structure in which a verb or an auxiliary precedes the subject. E.g.: "Here comes the sun."ed.

Even if emphasisSpecial importance or attention given to something. E.g.: All I wanna do is have some fun.es that something will happen whatever the condition is. It is possible in all types of conditionals.

I will wear my red shirt even if you don’t like the idea.

In the if-clauseA group of related words containing a subject and a verb. of the first conditional we can use should (to express that the condition is less likely), can (permission or ability), will or would (willingness, insistence and refusal), must (obligation) or may (permission).

The auxiliaryA helping verb used with main verbs to express mood, voice and tense. E.g.: I can't stand when I am disturbed. ("can", "am") can is used here to express capability.

Winters in Minnesota can be really cold.

For annoying habits, typical of a person we can use would. This usage sometimes implies criticism and has an emphaticSpecial importance or attention given to something. E.g.: All I wanna do is have some fun. effect:

If superlative adjectiveA part of speech that modifies, qualifies or restricts a noun or a pronoun. E.g.: The apples are ripe. ("ripe")s (especially the first, the last) are used, an infinitive structureThe way in which the parts of a sentence, clause or expression are arranged. E.g.: make somebody + infinitive in "The teacher made me rewrite the composition." can replace a defining relative clauseA group of related words containing a subject and a verb..

Geoffrey was the last to understand the joke. (= Geoffrey was the last person who understood the joke.)

If we want to express an actionA general term expressing that somebody or something does something in the passive voiceThe form of the transitive verb that shows whether the subject acts (active voice) or is acted upon (passive voice)., a passive infinitive is used:

We use the passive voiceThe form of the transitive verb that shows whether the subject acts (active voice) or is acted upon (passive voice). when we want to avoid naming the specific person responsible for an actionA general term expressing that somebody or something does something.