• to attend to sg, to hearken unto sg, to listen to sg, to mind, to take note of sg
• to follow a conversation
• to keep the eyes peeled
• to keep one's ears open
• to keep a close watch on sy, to keep a close watch over sy
• to stand silent and intent
• lookout, monitor, observer, observing
• attention, consideration, courtesy, heed, interest, note, notice, regard, respect, thoughtfulness
• now then!, pay attention!, please attend!
• attentive, considerate, mindful, narrow, observant, observing, perceptive, thoughtful
• to come into consideration