CAI

There are about 14 Chinese characters that are spoken 'cai'. The sound-determining element in about half of them is 采 = cai(3) = to pick. Another sound-determining element that occurs in several characters is 才 = cai(2) = ability.

cai(1)

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cai(2)

才 = ability

The two-character word with the same meaning is more commonly used.

才能 = cai(2)neng(2) = ability

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材 = wood (could also be firewood), timber

The single-character version is rather theoretical; in spoken Chinese, the two-character version is always preferred:

木材 = mu(4)cai(2) = timber (used in construction)

器材 = qi(4)cai(2) = equipment and material (used on shop signs)

身材 = shen(1)cai(2) = figure

A possible praise for a good-looking person:

你的身材很妤. = Ni(3)de(-) shen(1)cai(2) hen(3) hao(3). = Your figure is very good.

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cai(3)

采 = to pick

This word is in common use as single-character and morpheme.

别采花! = Bie(4) cai(3) hua(1)! = Don't pick flowers!

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彩 = a lot of color

你的衣服很彩. = Ni(3)de(-) yi(1)fu(-) hen(3) cai(3). = Your dress has lots of colors.

彩票 = cai(3)piau(4) = lottery ticket, lottery

中国体育彩票 = Zhong(1)guo(2) ti(3)yu(4) cai(3)piao(4) = China Sports Lottery

中国福利彩票 = Zhong(1)guo(2) fu(2)li(4) cai(3)li(4) = China Welfare Lottery

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cai(4)

菜 = vegetable, food

While the single-character can be used, it is usually better in spoken Chinese to use  the two-character words. 

青菜 = qing(1)cai(4) = vegetables, especially green vegetables

买菜 = mai(3) cai(4) = to buy groceries (not just vegetables)

我要去超市买菜. = Wo(3) yao(4) qu(4) chao(1)shi mai(3) cai(4) = I will go to the supermarket to buy groceries.