"only if...then...;as long as...then..." 只要…就…

只要…就… is used as a pair to form a conditional sentence. 只要is movable. It may be placed before or after the subject. 只要is usually used correlatively with 就 to mean “as long as” and 就connects the result.

(Subj.) +只要….+ (Subj.) + 就 ….

Example:
1. 只要你诚信，生意就会好。
Your business will get better as long as you stick to the principle of good faith.
2. 你只要答应这个条件，我就帮你忙。
As long as you accept this term, I will help you.

Substitutive drills: 
   贵公司   只要      付定金，我们就签约。
                只要      你们保证质量，我们就能订货。 
                只要      你们同意，我们就开始合作。
                只要      商品质量好，我们就有人买。