Typically it is clear that these creditors can sue you, but the more important question is whether they will sue you. Creditors do not always make rational decisions. The lawsuit process is slow, somewhat expensive and often unprofitable as a way to recover money from people who have few assets. If the creditor can do something else more effective, it will. For example, a creditor will generally not choose to go to court if, instead, it can repossess your car, foreclose on your house or terminate your utility service.
Creditors are unlikely to file a collection suit when the amount of the debt is small.
Creditors are unlikely to sue if you dispute the debt and threaten to raise a reasonable defense. Creditors are unlikely to sue when you are making small payments even if they are less than the creditor demands. Creditors are not likely to sue when that creditor has no history of filing suit. Collectors often threaten other actions instead of or in addition to lawsuits against you. They are unlikely to carry out these threats.