せっかく and のに are used together when great effort has been put into something, yet that effort may be going to waste.
せっかく and だから are used when a rare or unexpected situation has come up, and it would be a waste not to make use of it.
つもり marks the speaker’s conviction for having done something when following a past-tense verb.
らしい generally expresses conjecture based on what the speaker believes is reliable information they have heard, seen, or read.
Past experience is conveyed by appending ことがある to the past-tense form of a verb. こと turns the phrase before it into a noun.
Appending たい to a verb stem expresses the speaker’s desire to perform an action.
かもしれない is a combination of the interrogative particle か (questioning), the inclusive particle も (“even”), and the verb
When used as a helper auxiliary verb, 見る indicates trying something to see what it’s like to do, or what happens when it’s done. It appends to a verb in its て form, and is often written as みる.
The verb 直す loses its original meaning when it becomes a helper auxiliary verb. Appending 直す to a verb stem gives the meaning of re-doing an action, with the intention of doing it better than before.