I left out the following sentences. Thank you very much, Writeacher.
1) I think everybody would work at a passion but many times (mistake) this is often not possible.
2) If I worked, I would work at a job because I'll need (I need) to put aside money for me and my family.
3) I wouldn't like a boring job or one which wouldn't be motivating.
When I'll work, I will certainly work at a career.
4) If you (better someone) works at a career, then it is the prospects of promotion and the opportunities of development that motivate you.
1) I think everybody should work at something he/she is passionate about, but many times this is not possible.
2) If I worked, I would work at a job to put money aside for myself and my family.
3) OK
When I'll work, I will certainly work at a developing a career.
4) If someone works at a career, then it is the prospects of promotion and the opportunities of development that motivate him or her.
In 1 and 4, you can write these either way. Both are considered correct.
he/she ... him/her
he or she ... him or her
No problem, here are the corrected sentences:
1) I think everybody would work with passion, but many times this is often not possible.
Explanation: To correct the sentence, change "at a passion" to "with passion" to express the idea that one would like to work with enthusiasm and dedication.
2) If I worked, I would work at a job because I need to put aside money for me and my family.
Explanation: To correct the sentence, change "I'll need" to "I need" to maintain consistency in verb tense.
3) I wouldn't like a boring job or one that wouldn't be motivating. When I work, I will certainly work at a career.
Explanation: To correct the sentence, change "wouldn't be motivating" to "that wouldn't be motivating" to clarify that it refers back to the previously mentioned "one," and change "When I'll work" to "When I work" to maintain consistency in verb tense.
4) If someone works at a career, then it is the prospects of promotion and the opportunities for development that motivate them.
Explanation: To correct the sentence, change "better someone" to "someone" to make the sentence grammatically correct, and change "you" to "them" since you are referring to someone in general, not specifically addressing the reader.