ADV

carefully, closely
precisely
directly
It is not possible to observe this phenomenon directly, but its effects can be seen in the rise in global temperatures
actually
It is the parents who actually observe these behavioural problems in their children
just, simply
You can learn a lot by simply observing
generally, normally
quietly
She stood there, quietly observing the domestic scene
secretly
experimentally
This phenomenon has been observed experimentally

VERB + OBSERVE

be able to
be possible
be difficult to
be interesting to
It is interesting to observe the reaction of the children to these changes

PREP

from
unaware that she was being observed from the window

PHRASES

be commonly/frequently/widely observed
This behaviour is commonly observed among several species of finch
be easily/readily observed, an opportunity to observe sb/sth

ADV

correctly, justly, rightly, shrewdly
She correctly observed that there was very little difference between the two parties on domestic policies
drily, sardonically, wryly
tartly
coldly, coolly
'You took your time,' he observed coolly
conversationally
mildly, quietly
sadly

PREP

to
' It's easy for him to say that, 'she observed tartly to Michael,' but can he prove it? '

ADV

correctly, faithfully, scrupulously, strictly
This procedure must be correctly observed

VERB + OBSERVE

fail to

PHRASES

failure to observe sth
Failure to observe club rules may result in expulsion