Aim at

Aim at = To direct the intention or purpose; to attempt the accomplishment of a purpose; to try to gain; to endeavor; intention; purpose; design; scheme.
Example: I aimed at the public's heart, and by accident I hit it in the stomach.
Usage in Sentence: Aim at, not on or against.
Don’t say: She aimed on (or against) the target.
Say: She aimed at the target.
Note: Use the preposition at to denote direction: throw at, shout at, fire at, shoot at. Shoot (without the at) means to kill: He shot a bird (= he hit and killed it).

Thing

Thing = (i) state of affairs in general or within a specified sphere; matters: ‘Things are improving now.’ (ii) a special situation: ‘It is a remarkable thing.’ ‘I found the whole thing very boring.’ (iii) an action, deed: ‘How can you do such things.’ (iv) possession in term of object, clothes etc.: ‘Pack your things.’ (v) any attribute or quality as having its own existence: ‘The only thing I like about her is her sincerity.’ (vi) what somebody says or thinks: ‘She says the first thing she thinks of.’ (vii) detail or point: ‘Please check every little thing.’

Avoid using thing after an adjective when the adjective can be used on its own: ‘To obtain a bank loan when you don’t have a job can be very difficult.’

Note however the commonly used phrase a/the good thing: ‘The good thing about this school is that all the teachers are very enthusiastic.’

Something + adjective, anything + adjective, etc: ‘Did you notice anything unusual?’

The use of many things often sounds unnatural. Instead, use a lot, a great deal, etc.: ‘She said that she had a lot to do.’ ‘In just one or two sessions you can learn a great deal.’

Note also the phrase all about: ‘The best person to ask is David – he knows all about tropical plants.’ (= he knows everything about …)