Merlin is very customizable. There is always more than one way to do the things you would like to do, giving you thus the flexibility to choose your preferable work flow. Consider the insertion of activities. You can press command + N, call Insert > Activity, right click the outlines, the Gantt or net plan area to get the context dialog wherefrom you can select Insert > Activity, paste a copied activity from the same or another project, or drag & drop a predefined activity out of Merlin’s Library.

So it won’t come as a surprise to you, that there are various work flows when wanting to link activities. You can use the according button on the function bar, call the command (Edit > Link activities),  type successor or predecessor on the columns or in the inspector, press command + control + L to link the selection ‘finish to start’.

One possibility you might not know by now, is linking activities graphically.

To do so, roll the cursor over the activity you would like the linkage to start. Press alt and click and hold your mouse. Drag the mouse so that the cursor points to the activity you want to link with and release the mouse key. When doing so in the outline of the activities view or net plan, you always define a ‘finish to start’ linkage.

When using the method to link the activities bars displayed on Gantt, Merlin will show a black point near the activity’s start or finish depending on the current position of your cursor, giving you thus the possibility to define the necessary type of linkage directly. Check it out for yourself and see how easy it is.

Simply link the two activities as desired…

And see Merlin confirming the linkage.

You may want to check attached screencast