IF...
–conjunction
| 1. | in case that; granting or supposing that; on condition that: Sing if you want to. Stay indoors if it rains. I'll go if you do. |
| 2. | even though: an enthusiastic if small audience. |
| 3. | whether: He asked if I knew Spanish. |
| 4. | (used to introduce an exclamatory phrase): If only Dad could see me now! |
| 5. | when or whenever: If it was raining, we had to play inside. |
–noun
—Idiom| 6. | a supposition; uncertain possibility: The future is full of ifs. |
| 7. | a condition, requirement, or stipulation: There are too many ifs in his agreement. |
| 8. | ifs, ands, or buts, reservations, restrictions, or excuses: I want that job finished today, and no ifs, ands, or buts. |
Origin:
bef. 900; ME, var. of yif, OE gif, gef; akin to ON ef if, Goth ibai whether, OHG iba condition, stipulation
bef. 900; ME, var. of yif, OE gif, gef; akin to ON ef if, Goth ibai whether, OHG iba condition, stipulation

Synonyms:
1, 2. If, provided, providing imply a condition on which something depends. If is general. It may be used to indicate suppositions or hypothetical conditions (often involving doubt or uncertainty): If you like, we can go straight home. If I had known, I wouldn't have gone. If may mean even though: If I am wrong, you are not right. It may mean whenever: If I do not understand, I ask questions. Provided always indicates some stipulation: I will subscribe ten dollars provided (on the condition) that you do, too. Provided he goes, we can go along. Providing means the same as provided, that is, just in case some certain thing should happen: We will buy the house, providing (provided) we can get a mortgage.
Usage note:1, 2. If, provided, providing imply a condition on which something depends. If is general. It may be used to indicate suppositions or hypothetical conditions (often involving doubt or uncertainty): If you like, we can go straight home. If I had known, I wouldn't have gone. If may mean even though: If I am wrong, you are not right. It may mean whenever: If I do not understand, I ask questions. Provided always indicates some stipulation: I will subscribe ten dollars provided (on the condition) that you do, too. Provided he goes, we can go along. Providing means the same as provided, that is, just in case some certain thing should happen: We will buy the house, providing (provided) we can get a mortgage.
If meaning “whether,” as in I haven't decided if I'll go, is sometimes criticized, but the usage has been established in standard English for a long time.
对...
我也是个人.
我也是会不开心.
但是你知道吗?
或许你只看到我的嬉皮笑脸.
在我好强的伪装下也有一颗脆弱的心.
但这又有谁会知道呢?
也许对每个人我只是个每天都很开心的人吧...
我开始累了.
你知道吗?
